The context here was replacing an outlet or a light switch with a Zigbee version to create an invisible router (i.e. not have a dongle hanging off the wall).
I’m making progress. I’ve identified a location where I’ll have an outlet added. I have an extension cord run for the time being and I’m moving devices around. Will report back once that’s done. 
Interesting; now I understand how their system works.
You’re right, there’s no access to the junction box (without drywall surgery) but the electrical connections are accessible.
FWIW, given the great lengths this system has gone for aesthetic reasons, it seems a shame to connect a bulbous Zigbee plug to it.
Hence why I said in one of my replies about it if it can’t be popped out as I had a feeling they would have a design feature to use a tool or what not to give the access.
My thoughts exactly. I’ve made things more difficult for myself by having sexy outlets.
I’ve made significant progress here by doing the following:
All that remains now is to replace my aqara door sensors which refuse to connect to the sonoff router. Sigh.
Thanks everyone for your input!
I… I can’t even begin to comprehend an outlet I can’t access. I’m almost (not not entirely) positive those wouldn’t be allowed in my particular jurisdiction because exactly what you said, T… At the very least it would cause a significant conversation with the inspectors…
Here we aren’t even allowed to open the outlets. You need a certified electrician for almost everything.
I have never seen them sold in local home renovation stores (eastern Canada) so best case is they’re speciality products or, worst case, don’t meet my province’s electrical code.
Either way, I won’t deny they look very sleek. However, in addition to their higher cost, their installation requirements in drywall, and especially in ceramic tile, are more labour intensive than simply making a rectangular hole. Those looks don’t come cheap or easy. Slapping on a wall-wart seems counterproductive.
These electrical outlets are for the truly aesthetic-obsessed (which I am).
I only have them in the areas of my apartment where an outlet must exist and cannot be hidden. All other outlets in the apartment have been moved behind furniture.
I like my technology invisible.
Perhaps you can put a Zigbee plug into an outlet hidden behind furniture … whatever is closest to the dead zone. Even if it’s not close, it’s better than nothing and inexpensive.
The problem is the apartment is sorta long and down the middle of it there is one pretty outlet and nothing else. And that’s the dead zone.
The solution I’ve landed on is adding an outlet in the closet in that hallway.
For my own education, what type of apartment complex allows its tenants to modify their dwelling’s electrical system?
Or is a condominium?
It’s a condo which I own here in NYC. By law I cannot modify anything myself. I have to hire a licensed electrician.
When in doubt, add more Zigbee Router devices 
When it comes to Zigbee networking mesh it is almost always best to just have many “good” Zigbee Router devices than only a few “great” Zigbee Router devices, but still, having a few “known great” dedicated Zigbee Router devices placed in strategic location can be a very good idea, and that is something that I sometimes recommend to new Zigbee users that plan to start with a few devices before they add more, and if they do not get will not get enough coverage or range needed for their entire home.
There are also some specific Zigbee Router product tips about that here → Zigbee networks: how to guide for avoiding interference + optimize using Zigbee Router devices (repeaters/extenders) to get a stable mesh network with best possible range and coverage
Personally I can stongly recommend convert a few of ITead’s “Sonoff Zigbee 3.0 USB Dongle Plus V2” (model “ZBDongle-E” based on Silicon Labs EFR32MG21) into dedicated Zigbee signal repeater / Zigbee range extenders by flashing them with Zigbee Router firmware and powering them with a simply USB-chargers. While maybe not the prettiest solution to look at, if you make sure they are permanently powered then joining/pairing three or more to your Zigbee network and spreading them around in your home will create an extremely stable backbone in your Zigbee network.
Action: Buy a few known good dedicated Zigbee Router products and place them strategically as Zigbee repeaters. Personally, I suggest buying and adding at least three such devices.
Tips
That is actually not entirely true. All types and models of Zigbee Router devices are definitely not created equal. How they perfom will depends on exactly what antenna type and design, Zigbee radio chip model used, Zigbee stack revision, Zigbee firmware version and configuration.
Most commercial mains-powered Zigbee Router devices will not have a radio chip or firmware configuration that offers the same performance as a DIY Zigbee Router made from a convertered Zigbee Coordinaor dongle with external antenna. Older chips also ussually have worse performace than newer chips.
Yes it is true that there are government regulations for the maximum transmit power-level for low-powered devices (around 14+ dBM in Europe and around 20+ dBM in North America), …but that does not mean that everyone configure their to use the maximum (fact is that most devices that ship use much lower transmit power than maximum allowed), nor that everyone follows the regulations.
Regardless of avove, relocating your Zigbee Coordinator dongle will be among the most important steps.
Begin by relocating your Zigbee Coordinator dongle by using a longer (shielded) USB extension cable and make sure connect it to a USB 2.0 port (and not a USB 3.0 port) or specifically use a USB 2.0 cable. EMI/RMI/EMF interference can easily kill signal reception for the Zigbee Coordinator, which is why it is so extremely important to keep it away from all possible sources of interference and make sure that the radio frequency range of your WiFi channel(s) do not overlap/conflict with the radio frequency range of your Zigbee channel. Again, that and more is covered here → Zigbee networks: how to guide for avoiding interference + optimize using Zigbee Router devices (repeaters/extenders) to get a stable mesh network with best possible range and coverage
There are also some specific tips about that there, including how to convert an Ethernet cable to make a very long (but passive/dumb) USB extension cable by buying RJ45 conversion adapters → Zigbee networks: how to guide for avoiding interference + optimize using Zigbee Router devices (repeaters/extenders) to get a stable mesh network with best possible range and coverage
You could do that with “zha-toolkit” but understand that in your situation there is no point with a before picture, that would just be a waste of time at for you right now in your current situation. You first first need to take action to sort out all low-hanging-fruit issues before troubleshoot any deeper → Zigbee networks: how to guide for avoiding interference + optimize using Zigbee Router devices (repeaters/extenders) to get a stable mesh network with best possible range and coverage
Also understand reported RSSI and LQI values can sometimes be arbitrary and not always useful, read:
and
That is correct. There are no such things. Time to add that to docs → Mention another Zigbee limitation in ZHA docs by Hedda · Pull Request #33417 · home-assistant/home-assistant.io · GitHub
…and what do you know, that is also covered here → Zigbee networks: how to guide for avoiding interference + optimize using Zigbee Router devices (repeaters/extenders) to get a stable mesh network with best possible range and coverage
I worte that guide so that I would not have to sound like broken record that repeats itself 
Here’s a little before and after of the changes I’ve made. Everything will be green except the furthest door once I replace the aqara door sensors (which refuse to talk to the sonoff router).
This is more like how it should look when you have routing devices setup in the mesh:
ignore the red one in this one as that is an aqara t2 relay I am waiting for an electrician to install but have it already paired and setup.
That does NOT look good, there does not look to be any mesh networking going on at all. You should add many more Zigbee Router devices. Yeah I going to once again refer you to the read and try to follow the best practice this here → Zigbee networks: how to guide for avoiding interference + optimize using Zigbee Router devices (repeaters/extenders) to get a stable mesh network with best possible range and coverage
FYI, Aqara’s Zigbee devices are infamous for not automatically moving to better/closer Zigbee Router devices on their own, it is well known within the community that you will need to manually re-pair/re-join Aqara devices after you add more Zigbee Router devices.
Most other Zigbee devices revealuate neiboring Zigbee Router devices and usually automatically move around once every 24-hours if there are any better/closer Zigbee devices available.
I’ve actually repaired the aqara sensors multiple times to the sonoff router and they just go straight back to the coordinator. Even though the router is much closer. I’ve already ordered some sonoff door sensors to replace them.
The topology I am going for is essentially a linear backbone based on sonoff routers with a SkyConnect coordinator. Assuming those devices are robust (which is perhaps a poor assumption) what is the value of adding more routers to get some meshing going?
Others have mentioned powered sockets, and the Ikea Tradfi smart bulbs (mine are gu10) work as relays okay. I’ve got three in my house and they’ve definitely boosted signal everywhere.
Did I actually say that again? (Too many Z devices and not enough Z’s here).
