tweakCustomInventoryScreenScale renders improperly as shown in the below image.

This does appear to be a MacOS only issue, similar to FlashyReese/sodium-extra-fabric#297 and ramidzkh/fabrishot#49.
After resizing the window and then putting the game back in fullscreen, it still appears bugged as shown here:

This issue is mostly for documentation purposes.

Which exact mod version is this in? I know the 1.12.2 version had this issue at one point, but I think it should be fixed at east in the Ornithe version, although I don't remember for sure. I don't remember if the latest LiteLoader version has the potential fix or not.

I'm using version 0.19.1 of the mod for 1.20.4 (https://masa.dy.fi/mcmods/client_mods/?mcver=1.20.4&mod=tweakeroo), but if I'm correct, LiteLoader 1.12 is still the main development version of this mod.

Oh I had forgotten that the recent mod versions also have this option...

LiteLoader 1.12.2 was the main development version up to last Christmas, when I moved the main development to the Ornithe 1.12.2 branch.