Belt drive fixed

The only issue I can see at the moment is the front sprocket hitting the chainstay, so i'm going to need a much longer BB and some spacers, but it should be fine.
It wasn't cheap, but then obsessions rarely are.

This sounds great!

The front belt ring is pretty wide, so expect som issues there, especially with a 55T. I have mine (46T) mounted the on the outer spot, on what was a MTN triple. I have removed one of the driveside BB spacers (external BB) for 'belt-line', and now have very little clearance to the chainstay. This is on a frame designed around the beltdrive system. If you space the Belt-ring out you may find the belt sliding of the rear sprocket. The belt system is very sensitive to belt-line.

I'm sure you'll get around these issues. Best of luck. Sounds like an interesting build.