There was the performance of the Switch version at PAX, but Igarashi explained that with overheating demo units. It's the kind of excuse where you can't be sure if it was really entirely the fault of demo hardware or if the game itself had issues. The performance target of the Switch version is only 720p@30fps, so that indicates that this version is an afterthought and may not even hit that target upon its release.
First I've heard of the performance problems in the Switch version.
On the other hand I pre-ordered a physical of this blindly, and consiously don't read much about it. I was really impressed with Curse of the Moon, even if that game is really short, so I have my hopes up for this game.