You can always post your mod here, or even start a new thread for the mod by opening a ticket. "Degenerates" like you will be happy to download it!Dang, man, I know you're not as much of a fan of pregnancy and all that but honestly the pregnancy update elevated this game into one of the best pregnancy games on the damn site so I really hope you consider letting them get preggers more than once, especially on sandbox/21 week+ games—any excuse to see those one-off incredible (except smoking gwen...) preggy renders without having to reload a save or open up game files really.
To address your points:
First: Technically the code supports it, I simply removed the limitation for the impregnation option being disabled if they'd already had a baby. It's only a little screwed up in that you can still try again on the week or two after and it'll reset the preggy timer which can lead to some inconsistencies, so really shouldn't be much work to fix it. Minor text alterations can be changed so subsequent breedings don't make it seem like it's their first time as well, for story consistency. I mean I would genuinely offer to change the text/code myself there if you don't want to as well.
Second: With how quick it all is anyway, you can waive that away recovery time with your magic "alpha radiation" wand, or give like a 1 week grace period. Since the whole place is supposed to be designed to make babies, why wouldn't they logically have some sort of nursery & someone to look after those kids somewhere as well? Even Suki herself says they're supposed to be baby popping machines (and is mentioned by other characters too), and with such quick pregnancies, why not? More babies the better, right? Additionally, the only girl I even noticed being affected by the pregnancy outside the harem scenes was Amy's render in class and refusing the spliff, so it doesn't seem like other limitations for characters you mentioned like Penny not going scouting if she was pregnant seem even be there with the current preggies anyway (Michiko still teaches fighting skills for example).
Final: With 8 week pregnancies, 3 weeks in the harem before impregnation, working towards even getting some of them in the harem and 1 impreg/week, you can't even feasibly finish many pregnancies before the 20 week time limit without cheating anyway... Reimpreg doesn't seem to have any weight on that balance.
Just want to reiterate that pregnancy was an awesome addition, so thanks so much for it, and either way and I will happily continue to custom mod my game to support buggy reimpregs cos I'm a degenerate like that, but do think it would be great to include in the base game especially for other like-minded degenerates.
As for Michiko still giving fighting lessons while pregnant, I will fix this for v0.7, I saw a couple of other things pregnant girls weer still doing when they shouldn't indeed!