Prevent changes to PO before released

Once a release strategy is invoked for a PO, I'd like to be able to prevent/lock the PO from changes until it has been released.

I noted that on the PR release indicators there is a way to set the PR to display only (via the field selection key).

I can't seem to find this kind of functionality as part of the PO release procedure. Does this functionality exist?

Thanks for any insight you can provide,

Angela Lee