This thread
https://gbatemp.net/threads/cartridge-information-collection.492311/ doesn't have any better answers for me than
https://gbatemp.net/threads/list-games-required-firmware-version.485959/ does..
If my cart update strategy is a gamble, maybe I should take the safer gamble of the paperclip. (I know people say the paperclip is totally safe, but I've nuked hardware with electricity before in my life a couple times, although it was always a case of faulty wiring in the house or once even my socks).
That said, if I could find a game that contained the 4.1.0 firmware update AND was a game I wouldn't mind paying, I'd definitely drop 20$ on it. That way if it doesn't work and I lose the gamble I still have a game I can play after using the paperclip (I don't intend to pirate games, I just want to protect my switch from nintendo updates (while still playing the newest games), and perhaps eventually run emulators and such on it, nintendo's backwards compatibility and virtual console systems are both total jokes).
Darkest dungeon, as well as kirby are both interesting choices that weren't in the first thread I considered. Although picking a game that appeared on both thread's lists might be ideal (like bayonetta). Or even just picking the worst (cheapest) which would probably be sushi.