Can the marketplace blocker be added after a contract is deployed

Gm - I am about to create my first manifold contract for a new collection and I am in the dilemma about royalties and the marketplace blocker.

Does the market place blocker have to be activated at the time the contract is deployed, or can it be added to an existing contract at a later date?

I understand I can opt out of the Marketplace Blocker App afterwards but would this action remove the code and be irreversible - So that the sovereignty of NFTs would be strengthened again? Or would there always be the option to turn it on/off?


gm - The marketplace blocker can be added after a contract is deployed and can be turned on and off at your discretion.

Thank you - and is this the same for the Operator Filter?