Each part has a set of buffs they accept, you should only need to add the PowerPlacebo buff to that list.

Alternatively, you can copy some of the entries in the mod.rules file that add that buff to the base parts and simply point it at your part instead.

I have not actually tested this functionality with another mod, so I cannot be straight enough issues that might arise from doing so.

See the main description for more details on adding support.