Not an expert, but just wondering, why 12:1 on the FMU? Protomotive uses a 4:1 on a 911....
Also, after watching a recent video of a turbo toasting a Golf, are you at all worried about the hot side of your turbo touching off anything close to it

? I know you mentioned it's not the final resting place for the turbo, but that looks a bit busy there.
Sounds cool, should be a great hp/weight ratio. I had an e36 328, what a great car, would have been good with another 50-60hp.