Not sure if this is a useful datapoint:
Without having read the recent updates about sleep mode, I inserted my Persona Q cart on Friday and left my 3DS on the home screen in sleep mode up till about late Sunday. When finally I went to play it, it crashed and subsequently failed verification afterward. I did take it out of sleep mode without launching anything once or twice though. It's been a couple of tries through the corruption fixer and I'm still getting unfixable chunks, so I might leave it in sleep mode again and see if anything changes tomorrow.
Also, the results screen text appears to be flipped? On the first run through, the result right before it completed was shown as
Unfixable chunks: 177
Fixed chunks: 571
But the results screen gave
Unfixable chunks: 571
Fixed chunks: 177