Right, right. I think this is a case that I'm presupposing things being out of reach simply because I saw under the hood already.
I can't get something like that to work with my rudimentary skills, I'm afraid. That would require messing with Enums that store who the father (in that way, but also variable ownership) of an impregnation point is and I just don't have that know how. (Presumably would require changing the minigame end conditions too.)
It would also require rewriting the checks for when impregnation can happen, which will likely lead to bugs when we open the doors for a behaviour that has been otherwise off limits until now.
And it would also require tweaking the futa opponent's selection process to also go after already claimed girls, and that is an entire black box of its own I haven't peered into.
Half the minigame logic would need to be rewritten and I have no debugging tools to make playtesting something like that remotely bearable.
Eyeballed it as well thinking of something similar, the logic isn't impossible to get done.
The major hurdles:
1. The logic that happens when a character gets impregnated would need to be changed to allow for it to be overwritten by either the MC or futa, without counting as an extra impregnation.
2. Instead of at 9 characters getting impregnated being the ending, the game would need to check if all the women are impregnated by MC or futa as the end condition.
3. Futa's character selection choice would need to be modified so that they'd still go after characters who are impregnated, but not by her.
Playtesting it wouldn't be too bad, if one had a save ready to play the minigame immediately available or removed the check gating the minigame from being playable from the start for debugging purposes.
Most annoying hurdles with how things had appeared to had been setup would be adjusting character selection choice & making sure the impregnation overwriting doesn't just let the futa or MC impregnate the same woman 9 times to reach the end condition.