Fate/Stay Night [Realta Nua] - Ultimate Edition - 2022

[Bohemian Waxwing]

Wait, I thought ratios between 4:3 and 16:9, such as 16:10 or 3:2, were fine? (which we've established are becoming increasingly common)
I thought the issues only applied to ratios taller than 4:3 or wider than 16:9 - am I wrong?

Indeed, only the 4:3 and 16:9 ratios have their own transition rule images, so only these will display perfectly. All other aspect ratios will have more or less pronounced glitches in transitions. Other effects seems to hold up reasonably well up to 21:9.
My recommendation is to play in 4:3, the ratio the game was made for, or if you are of a younger generation that can not mentally process 4:3 ratios, to use 16:9, if you absolutely must.