I didn't notice any issues with the Switch 2 version on my end (30 hours playtime), but I never played the game in handheld mode - only docked.

Sunset Heights, Frontiers Cyberspace City at night, the first few seconds of Planet Wisp, and the outside portions of Air Fleet.

If every act was split into 2 smaller ones then it would be so much better, because between S Ranks and Hotdog missions so much of the game is going through long stages with no checkpoints and plenty of ways to instantly die.

Rhea should've just been Kronos part 2 (as it's physically that already), and Ouranos could have had some sort of cool 'The End is coming to kill you' sky effect like a permanent sunset/twilight. It doesn't change the islands still looking like eachother, but it's something to make them different.