One could prepare a loop with different sounds in fixed intervals and set the interval (e.g. 4 seconds) in the clip properties. Loopy would then randomly (or sequentially for that matter) pick sounds from the loop and stop playing when the sound stops or after the interval.

An option to not stop playing for creating glitchy breakbeats would be nice too. In this case the playhead would simply jump around after a set interval in seconds, beats, etc. Crossfades would be great for granular synth functionality.

A totally fancy version of this would be the option where Loopy finds the sounds inside a loop (separated by silent breaks or transients - Ableton style) and assign start and stop markers automagically. This would allow for different sounds of variable lengths.

Linking the playhead's position to velocity would be another angle and also allow for multisampling within one donut (e.g. different versions of one instrument). In this case a simple ADSR would be awesome too. This would move LP into 'classic' sampler territory.