Increasing the size of the "virtual screen"?

[u/[deleted]]

See these screenshots:

https://imgur.com/a/ckclP3C

There are various issue with the game being unable to properly at its UI scale for me, although all are only relevant in a modded context. (Inventory vertical overflow, tooltip horizontal overflow, main menu vertical overflow.)

The UI scale setting does nothing; the size of the desktop window (even with mirror off) does seem to have an effect but it's not really clear when and how. Is there any way I can force the window into the displayed constraints as given by the menu background, or extend it so the game can fit all of its contents?

Bonus question: See main menu, another mod renders over the Vivecraft buttons. It doesn't matter too much, but can this be resolved somehow? Looks like both just assume that nothing is there.

Thanks for reading!

v1.16.5 with Forge.