It’s cute to say that people borrow 50K per year because they can wipe it out in 10 minutes with their alleged investments— but the statistics on parent plus loans suggest that this is an urban legend. Yes- there are a couple of Mitt Romney types whose money is tied up in long term vehicles with limited liquidity. But the vast majority of parents who borrow are people who don’t have the dough. Liquid, not liquid, long term capital gains are a problem, short term gains a problem are all irrelevant for people who don’t have the money.
If OP wasn’t concerned about the money OP wouldn’t have mentioned it at all.
I’d love to see evidence that people borrowing 200K for college (50K times four years) do so because their portfolios can’t be liquidated quickly enough to pay a bill (which they’ve known was coming for aprox. 18 years).