Solved TL;DR Since Patch 0.6U9 there is an Extended OutSim format available that includes Wheel data

I am wondering if there is a way to get the wheel spin of each wheel. I know raf files have that information included, as I can see it in F1PerfView. do you know if there is a way to do this (possibly by recording raf files as the car is driven), and if not if there is a way to at least approximate it with outsim/outgauge data

I'm no programmer myself, but you might find this interesting. Recently, Live telemetry data has become available in a new customizable OutSim packet: https://www.lfs.net/forum/thread/93701
There's a float parameter for Angular velocity (AngVel) in radians/s in the OutSimWheel data structure of the new OutSimPack. Maybe you could use that

Thank you so much, this is the perfect solution. To be honest I didn't expect this to be that easy, or at all possible.