Hmm, if I remember correctly I just added on to events already in the game and made it possible to actually ask him (and Sally ofc) out on Valentine's, and then of course added their respective endings. Not many people know this, unless they're actively looking to befriend the unavailable options in the base game, but many events that are meant for the actual options will have choices in them that you can pick that then earn points with Dominic/Sally instead of the LI in question, so you could likely rely on those.
However, I know that sort of answer is incredibly vague and unhelpful, so thank you for bringing this question to my attention - I'll replay the mod myself (I made it so long ago that I can't remember the specific events I changed/added to) and then get to making a walkthrough for this mod 😊