Hi,
you got it wrong - i built both firefox52s in NetBSD 9.3... it crashes with the pkgsrc-2022Q4 base and does not crash with a pkgsrc-2020Q4. I used the pkg from zia just as a reference test and this one fails also with a base of 2022Q4.
Oh! 2022 versus 2020. I was reading that wrong. My bad. I noticed recently that firefox52 on Alpha has issues, too. Hmmm... John