I looked at this for quite a while and although I've done a fair few mods with Forscan, I don't think its possible to get this one done there. There's a guy on YT who did it by adding a proxy device between the windows and the control mechanism: The Most Amazing Mustang Mod EVER!!
That's brilliant news - at least you got it all sorted and your new nickname will be Chilly-Balls! Its great you saved the $600 but it is fun and satisfying doing it yourself anyway 😜
Damn, sorry that bottom blower replacement didn't resolve your issue. Yeah those T50 torx bolts were really in there - I used a breaker bar to get them loose. You should be able test your old bottom blower now its out, with a multimeter.
Another good video from the Ford Boss on replacing the blower: 2016 - 2019 Ford Mustang Heated Seat Motor Replacement - SSM From Ford Didnt Fix Original Noise (youtube.com)
Same here. Bought red VLAND tail lights in 2020 and they're still functioning just fine - I still have the white tail lights which I swap out for the national car (road-worthy) test (NCT) evry two years.
You don't need to remove the seat cushion either - the metal frame that the blower is attached to, can be unclipped and push back so you can access the two torx screws holding in the blower.