I think the issue being discussed here is the time it takes from pressing the 'join' button, or entering single player to the point where the vehicle selection/race button becomes available. This for me is what takes a long time now [even with an SSD] and clearing shaders/Cbash won't improve this.
Mine takes < 5 seconds from clicking SP to tracks/cars available.. @Mark Fuller, you're on the latest build?
Just tried mine in VR (SteamVR closed when I click SP) ~7 seconds before tracks/cars available. Steam is on HDD and Steam Library on SSD. I do have a fairly new beefy computer (< 12 months old)...dunno whether that is a factor though.....sorry not much help :-(
I tried moving all Locations and Vehicles (except the one I was using) to a back up folder so rFactor had to process fewer files but it was still slow (about a minute). The UI is a lot tidier though! (Moving them is almost instant rather than copying which would take quite a while.)
For me it is 2 min 4 secs ! Has to be taken into consideration that my workshop folder is on another non-SSD disk.