Not sure if this is an issue for YACL or XSO, but maybe add a little bit more padding to the sides of this menu.

Instead of this:

It could be like this: (this is done with image editing, so the background is a bit odd but I think you get what I mean)

This would be great to improve the user experience

Why? that looks awful?!

I don't see why the menu has to completely span across the screen, the buttons don't need to be that wide. I think it looks better this way tbh, it's more readable to me

For example, Minecraft's current menus look something like this:

YACL's menus (to me) feel a bit out of place compared to the other menus because of this:

• It's styled to fit in Minecraft. YACL's GUI is designed to fit right in.

I don't think there is much point in doing this. Width is very valuable in this gui, removing it for no reason isn't the best idea.