I wld consider wavetable or granular as sort of like processing?
Basically if the sample is the source of the initial sound generation then it’s fine for me, it doesn’t have to sound anything like the original source by the end of the processing.
But if you’re using other synths or drum machines (or other sample packs) then it’s not really much of a restriction and sort of defeats the point imo. @Meddle do u agree?