Docker client to sync files with containers

You are correct that every start would require a new 2FA token, if 2FA was supported.
I have no intention of supporting it because it goes against the purpose of two-factor authentications.

While preventing syncs at every start of a container by checking that a library is already synced is possible, starting the container with a token of a 30 seconds lifespan hoping the library syncs before it expire does not make sense. What make sense are application passwords. Most online services that provide 2FA also provide application passwords for that specific use case.

There’s already a topic about that, I encourage you to take part in it: