FX Presets
FX have been significantly expanded with parameter options, and with the ability to run different FX on multiple tracks, preset saving functionality would be beneficial for faster workflow.
A more complex request here would be preset groups wherein 2 or more FX that play off each other in routing to create one singular effect could also be saved/configured. I think most users would just be happy with the preset saving option in general.
Ping-pong sample playback mode
Specifically with ‘Single Player’ in mind, this is used in a popular sound design technique with polyphonic samplers, where the different speeds of voices crossing over each as they scrub through the sample leads yields very distinct results.
Example: