I've noticed that in most cases, the level fade out happens right after the time counts down but sometimes it seems to take a second longer? I've tried mashing to see if that helps but it's still very inconsistent. Has anyone else encountered this or know why this might be happening?

Happens to me too, especially in 1-2, I don't know the reason though. Also I don't think mashing helps (but I still do it). I'll see if I can find out why this happens. And as far as I know igt and card (flower, star, mushroom) don't matter. Could be random too. But again I'll look into this.

I've been experimenting and I think I have a solution - once the timer counts down, mash briefly and then stop. My strategy for this has been to press A or B just 4 times quickly after the time counts down. It could also just be a placebo but it seems to be working so far.

From some observations it seems that the slow fadeout is dependent on the card animation in the bottom left corner. When the fadeout is quick, the card blinks twice immediately, but when its slow it seems to be delayed.