When the close button is disabled in the config, the space where it would be still takes up space on the menu. This can cause some visual problems, with Quark's sort button and Charm's inventory crafting table button overlapping each other, for example.

The slot mover was removed in my most recent PR from quark, do you think you’re able to add quark compat in compatibility mode or atleast disable the x if quark is enabled?

Quark is moving the button itself by checking for the presence of Console Experience as a mod. There is no easy way for Quark to also check if the close button option is actually enabled inside of Console Experience.