So just to play devil's advocate: is it really that much more work to build something entirely new in Tauri than to just do the porting work for releasing a GTK app on Windows/macOS?
I know it's annoying but it's not like it's impossible, right?
mupdf is the mupdf of epub; it supports epub and other formats beyond pdf¹. When I've had really large files I've used mupdf to read them a few times, as it seems to be far better at handling them than other tools.
I know it's annoying but it's not like it's impossible, right?