That is already possible. Much is often updated today.
Everything should always be kept up-to-date. We (and the manufacturers of e.g. swoolepush) constantly supply updates with bugfixes and security updates.
It can be done… But it would be better to set the versions permanently. I once described it for the 20.1 update:
So of course you have to make sure that everything fits together and you have to clean up Docker yourself. This is usually done with updates via watchdog.
I would take care of a nightly backup and let the updates run automatically. Updates are made to be installed.