I kinda figured that it's only a matter of time before someone makes a harness/bypass/BCM swap option. At this point though, I'm ready to just buy an aftermarket kit I can wrap over the rear view and call it a day.
@Jimmy07 told me a coconspirator has one running using a junkyard 2021 BCM hidden under his console.
I've been prodding a few folks to see if they could womp up an Arduino that could tie into the CAN bus and run one. Not sure how much a picked 21 BCM would cost...