Help with HiDPI on L13

Trying to find a good solution for HiDPI problems with some apps but can’t find any. I use mate desktop and programs such as fontforge have very tiny fonts and icons. If I scale to 2 they are too big and fractional scaling does not work. However apps like Thunderbird have reasonable size fonts and icons. How is this done? Because if I open thunderbird on an old window manager it has tiny fonts as fontforge on mate desktop.

So there must be a way to fix such issues. Unless it is thunderbird which knows how to behave on mate desktop…