I'm using Enpass in Mac OS Big Sur. The default font used is "AppleGothic", which is outdated (the default system font was changed 8~9 years ago) and ugly. The new default Korean font in Mac is "AppleSDGothicNeo.ttc" in /System/Libarary/Fonts folder. It has been the system font for many years and I don't think any active Mac uses "AppleGothic" in any place.
I suppose the default font setting for Mac used by qt toolkit still stays with "AppleGothic". Can you change the default Korean font setting (for all Mac) from "AppleGothic" to "AppleSDGothicNeo"? "AppleGothic" may stay but the preference should be lowered I believe.