Little tricky because of all the components, but here’s what I can get. There’s no separate ESP module
Ok…so the third image, the one with flash used, there seems to be a 8285.
It’s to fuzzy image.
Worst case scenario you need to solder directly to the ESP board.
On that tiny little 
esp8285? Some advanced soldering skills are necessary for that!
With some luck: RX,TX and GPIO0 are available on this solderings here (I would just tap with male dupont wires here again and do not solder):
I mean, I can solder. I do solder, but that is seriously tight (and i’m not a good solderer!!)
I think i’ll explore the ota option and 
I understand it might look hard but those solder points orange pointed at, are they too small?
If you take a Dupont and pre tin it at the tip then you can just push it on the pad and then just a quick touch with the soldering iron and it’s on.
I would say that most of the pins is probably exposed down on the larger board. At the very least 3.3 and GND.
You could read the pinout of the 8285 and try with the multimeter to see where the pins go.
The good thing about this tuya convert is ones it is setup and functioning the hardest part is done. Then it doesn’t matter much if you ota-flash 1 or 10 plugs with it. Because you dive it in anyways because of your other “glued” plug it might be worth to “post pone” the serial experiments as you just might be lucky to free the device ota 
I found that many of my TUYA devices were too aggressive on polling and tied up EVERYTHING. Migrating away.
that’s why we better do a local push instead 
So… can anyone recommend a chap USB Wifi dongle that supports AP mode? I’ve just been through two that apparently do, but only under Windows… 
For tuya convert? You don’t have by chance a raspberry (with integrated wifi) flying around - this is what I used back in the days. Worked a treat 
Ah, sadly not. In fact I built my HA on a thin client simply because I couldn’t find a Raspberry Pi for love nor money!
Right then - so, back to the task at hand, I have finally found an adapter that works in AP mode in Linux
Its a RTL88x2BU based device, which is dual band
It was a bit of an effort to get it set up in Ubuntu (using method from here and driver from here )
Anyway, all up and running but I have an issue where it only seems to broadcast the tuya-convert flash network on a 5ghz band (which is no good for any of the tuya devices…)
Long shot, but does anyone have any idea how I might restrict the device to 2.4ghz instead?
EDIT: Got the answer on the driver github… added add
hw_mode=g
ieee80211n=1
in the hostapd.conf in the tuya-convert and it worked
Well… it sort of worked… my firmware is too high so no OTA flashing