There's a known issue with the wires for BLIS getting abrasions from rubbing against the bumper. Not sure if that would impact your HVAC but could be the cause of BLIS issues in the rain. I believe it's possible to see them from under the rear.
Has anyone been able to order a Braptor cluster to retrofit? I tried but the dealership asked for my vin and mileage. They then tried to order it twice and both times Ford sent the “correct” semi-analog cluster for my Bronco instead of the Braptor part number.
Having "Pitch & Roll" selected as the side screen option caused all sorts of freezing and audio glitches for me when shifting into reverse. Switching it to anything else fixed most of my issues.
Apparently Forscan can do a camera 360 calibration but you have to find a parking lot with really well painted/contrasting lines. F150 folks have to do it when they add trailer tow mirrors:
https://www.f150gen14.com/forum/threads/camera-calibration-when-upgrading-side-mirrors.15293/