Can I disable Cross-Progression or unlink my accounts after enabling it?

Yes. However, if you unlink an account after it has been merged, all progress and purchases will be set to the state they were prior to the merge, potentially causing a loss of progress / virtual goods on that platform.

When you unlink your platform account from your Behaviour Account, you'll have to wait 60 days before linking a new platform account (of the same platform) to your Behaviour Account. You will also have to wait 60 days to link that platform account to another Behaviour Account.