OK, I think you mean window size rather than aspect ratio? (which is also good to support, but the relatively small world + small text issue appears when stretching window, even at same aspect ratio). So supporting different sizes should be worth for Android anyway. In this case it’s more important to have bigger text (which also acts as button), this was my main issue when playing text adventure / visual novels on Android. I know you can play with stretching modes in Godot to decide whether to scale text or not with world, so you could try that; or just manually set the size when using a dynamic font.
I meant aspect ratio, in the sense that the reason why I couldn't get good scaling behaviour in the first place is because none of the scaling options in Godot seemed to work satisfactorily when stretching the window into both a widescreen-y shape and a more mobile-y portrait shape. But deciding not to try so hard to support mobile, and instead having a fixed aspect ratio, would free me up to use more sensible scaling options.
Might need to make a separate export for mobile with different settings. I dunno, I'm bad at dynamic UI layout.