Effect of upgrading temporal on currently running workflows

Hello.
I am using python temporalio 1.0.0
I have thousands of running workflows.
would be there any harm in upgrading temporalio from 1.0.0 to 1.6.0 on the currently running workflows?

and in case I noticed something weird and I needed to revert the deployment, would going back from 1.6.0 to 1.0.0 harm anything?

I think temporal must be backward compatible, but I just need to make sure.

This should work for SDK updates. But please test this scenario before deploying to production anyway.