Yep, I can pull off most everything except the reverse... I've never heard a convincing reverse algorithm for the FV-1 that didn't have weird issues.
I'll have to dig out the XP-300 to refresh my memory on exactly how it behaved but it was basically an all wet delay where pressing down the pedal would slow down the playback, then around the mid point playback would start speeding back up in reverse. Similar to a pot controlling a tape capstan motor speed where noon was full stop, CCW was reverse, CW was forward.
I have some working prototypes for the ring mods, bit crushers, sample hold, and even a not so terrible version of the synth patches.
The synth patches are basically gated shimmer reverbs with 4th and 5th harmonies instead of (or in addition to) octave.