The pro version of Overleaf supports offline work with a simple trick: every Overleaf document can be accessed as a git repo. It's a bit limited (there's no branches or tags, and it breaks the "track changes" feature) and trying to convince the average researcher to learn git is a challenge, but if you know git it works quite well.
JCGoran|2 years ago
I really hope the typst webapp gets git support soon so it at least gets feature parity with Overleaf in this department (issue tracker: https://github.com/typst/webapp-issues/issues/25).