Preventing Forme reversion

[ABZB]

In Ultra Sun, I want to stop a specific Pokemon Forme that normally reverts at the end of battle (and in fact, will revert in-party if it is set to that form in Pokehex), but not stop any other Forme reversions - is that possible?

I know that it is possible to disable all Forme Reversions (as the 3DS randomizer program has that as an option), but I do not know if it is just disabling the script that handles that, or if there is a(n implicit) lookup table or flag somewhere that I can edit.