Just wanted to get your opinion on running from a pi vs synology. Have you found the pi to be more stable for your z-wave devices?
I’ve been running HA on my Synology box similar to how you were doing, and experiencing the same type of issue where I lose connectivity to my z-wave and zigbee devices every couple days and have to either restart HA or the entire Synology.
Hi @Robby_C! Indeed, as I reported I had some issues using synology losing z-wave connection every 2 or 3 days. Just as you are experimenting right now, other than that, I didn’t have any more problems with synology and docker. However, as I could not find out the reason I bought a pi and installed hassbian and right now, I don’t have any problems at all regarding my z-wave devices, all is working fine.
If you are suffering the very same issue I do recommend you to install hassbian or hassio on a Raspberry Pi 3+, I believe you’ll be happy. Hope that helps.
FWiW, I’m seeing the same issue, my zwave network stops working from HA after 1-2 days, along with my caseta network; my config is a Rpi with aeotec zwave antenna, latest hassio but i’ve seen same behavior across severals updates. I’m a home assistant novice so I assume its something in my config; at first I thought it was some screwed up automations I had with my caseta lighting that was generating errors in my logfile. I fixed that, those are clean now, but sure enough, after 2 days, zwave/caseta not working, my wifi devices like ecobee thermostats are working fine. I’m just starting to debug it, nothing obvious so far. Rebooting the Pi works everytime. I’ll try to find time to debug this and put what I find here, or at least enough clues for someone to say “Aha! I know what that is!!” 
Sorry to hear that, when that happened to me I couldn’t find the reason why, and it only started to work well again after reinstalling on a new hassbian setup on a new raspberry pi.