true for eg MS' C++ extensions or copilot - they actively block installing and running it on codium, based on some internal "app name" config of the IDE.

there's a workaround for that though. install both codium and vsc, install extensions on vsc, symlink the ".vscode" folder to ". vscode-oss", and edit codium's app info json (forgot filename) to match vsc's (mainly the "app name").

last step needs to be done after each update, but can applied with a script, happy to share if anyone needs it. Just make sure the installed codium- and vsc versions match.