Getting my set of BMW seats with belts soon...

Ever got these installed in the car? I'm looking into bmw seats myself.
I have them bolted in temporarily, but it’s clear the base of the seats are taller, I’m thinking about using dropped floor pans. It’s unclear if the seats are going to deman being hooked up to an ecu, I’ve read conflicting reports on that. Not going to know for at least 8 months.