Correct,
the implication if Lena doesn't go is that the game still happens and Jeremy chooses Ivy at the end, same as if Lena had been there but let Ivy take charge
I missed this early reply, but while it hasn't been 100% consistent, that seems to be the general logic (there are other caps earlier in the game). The main thing to me is that in chapter 8 it felt easy to reach those caps, while I was focusing on increasing my stats, I was still playing a route that didn't involve defying Minerva (massive source of stats for Ian). I guess Ian's stats are just really inflated compared to Lena's, which actually makes me speculate for the following chapters: