Did some testing and force storm is not totally disabled by the presence of psychology in a save (also have Cults and cosmic horrors installed).
Psychology is save-friendly since it leaves old pawns untouched by it. Force storm still fires and kills those old pawns. In the save file, old pawns and Psychology pawns seem to have a different class.
Vanilla pawns start their savefile defs with <thing Class="Pawn">
Psychology pawns have <thing Class="Psychology.PsychologyPawn">
Similarly, cosmic horror pawns from the Cthulhu mods use this:
<thing Class="CosmicHorror.CosmicHorrorPawn">

Force storm doesn't work on those either. Could be it's only coded to target those vanilla pawns. Seems fixable, but might be messy

Edit: Someone says the Zombie Apocalypse mod has a similar change (presumably replacing all human pawn classes), and it uses the "BiteablePawn" class.