Update on-chain after mint (OS royalties issue)

Right now, we have created a contract on Nov. 30 (bad timing). I’m wondering what would be the solution to enforce royalties on OS in case no deal happens between Manifold and OS.
Is there any way to force on-chain royalties once the contract is deployed either by registering extension afterwards or by transfering all the tokens to a new contract?
We thought about creating a new contract for the 2 upcoming drops and ask OS to merge it with the other one, but they answered us that “A collection that does not enforce their fees on-chain won’t be able to be merge together with a collection that does enforce creator fees on-chain. If the new contract has creator fee enforcement on-chain, it would be it’s own separate collection.”.
Any solution? Our new drop is supposed to happen on Dec. 8 so we’re trying to find a solution quickly.

Just an update that might shed some light on things!