Thanks for the suggestion. I have actually looked into added a quit function several times now, but every time it results into a software crash. I will keep looking into it.
Indeed there is no way to do it without software crash. But on the other hand, almost no switchgame has a quit button. That's just not the way you close them.when you press the home button you are back in the menu. If you start a other game the old one gets closed. If you press on the current running game it will resume gameplay (this is also working with homebrew, as long as you started it with title takeover)
Only a few have it (like Blobby Volley 2) but many apps have it including NX-Shell, Goldleaf, App Store NX, RetroArch ... However I don't know if that is doable with LovePotion and Shrike is right: There's the home button which is fine unless it kills the app while creating a savegame (which shouldn't take too long for Snake lol).