It’s the clutch check valve. You can disable it by pulling the core out with a pair of (very small) needle nose pliers. Experienced the same issue when I put the SMF in my car.
There’s this delay, almost like a lag when shifting fast at high RPM’s.. before the next gear hits. Really annoying and makes it impossible to bang through the gears quickly when doing pulls. Does the R come with a CDV (Clutch Delay Valve) ? There are tons of threads over on the 335 forums…
As for the clutch pedal being low, you didn’t properly reset the pressure plate when you installed it; you need to take it all apart and reset the pressure plate before installing it on the car.
There’s a moderately expensive tool that does this, or you can make your own: