What would be the performance implications? Isn’t virtiofs theoretically faster?

Every other solution looks more elegant on paper but has lots of pitfalls

A very sane and fair comment.

Then I will try NFS and get back to you. Thanks :)

The cloud binary is proprietary and it’s not supported by rclone unless I find out how the binary works but I doubt it uses something standardized like WebDAV underneath.

I can try but I might end up in the same situation as with virtiofs. The cloud drive will get unmounted and I will end up with an empty folder when I try to access it from the host.

The cloud drive is mounted on the guest, yes, but once I mount it with virtiofs in order to share it with the host it gets unmounted and I end up with an empty folder. bind doesn’t work either.