For pressroll to work, just one thing has to happen; the interval between two notes on your snare has to be below what you set the pressroll timeout as.
1) Confirm pressroll note is set to different note than the head, so you can actually tell when it's triggered.
2) Raise pressroll timeout to 200
3) Lower Retrigger to 1
4) Lower DynLevel 1 / DynTime 4
5) Lower threshold till self-triggering occurs, then raise by 1
6) If no self-triggering occurs, raise gain till it does. Then do step 5 again.
Pressroll notes should be happening all the time, with these settings. If they aren't, I suspect something is wrong with your snare pad... i.e. hardware issue