Sorry, I wrote that poorly. This has worn me down. I'm back on it today... and grateful for your help.
For background, I've flashed (hacked) many complex Android phones so I was confident, what could possibly go wrong?
The upgrade process
appeared to go fine. But it (or I) has muffed the TC portion of my M mod completely. It no longer senses resistance. Instead, it says .06 ohms regardless of atty. I believe (hoping & praying) this can still be fixed by flashing the device again because I have a lit display and it works in wattage mode.
Here's the abridged version of what I did yesterday...
I D/L'ed both SXi and the 120w (V2.2) firmware from
the Yihi SX Mini site. (per the Busardo vid) I installed the SXi and flashed the F/W to the device. This appeared to be a successful upgrade. I checked the device when finished and and it had V2.2.
But the resistance on the device in TC mode read .06 ohm and I got the 'dry coil' warning on the display no matter what atty head I put on it. It worked fine in wattage mode.
Then I re-flashed the same F/W a couple more times with the same result.
Then flashed the 120w F/W from
the Yihiecigar site... with the same result.
Then I tried to revert back to the stock F/W (v1.6) from
the Yihi SX Mini site and the display had garble on the temperature portions of the display. It was awful, and incredibly slowwww on the adjustments using the gravity sensor.
Then I flashed the 150w from the Mini site, then I uninstalled and did a clean unzip and re-install of everything... same result.
I was losing patience and over the next 4 hours, I flashed everything to it except Furbie firmware... alll with the same result.

Then I went outside and threw cats at passing cars for a while & went to bed.
This is my 2nd M Class (1st died) and Yeti Vape may wanna shoot me if I return this mod... if they'll even let me.
My M Class is my bestest fave mod. I've got a $20 PayPal bounty for the advice that recovers it. I don't wanna send it back again.
Thanks all.