One idea:

make sample chains contain 31 samples and one silent “slot”. then slice it to 32 slices.

that way, with a random LFO you can control the probability of something sounding:

LFO depth 31: 100% chance of hitting a sample
LFO depth 32: 1 in 32 steps will be silent.
LFO depth 64: ~50% chance of hitting a sample

etc…

I think it works.