Right now this is locked into a narrow band of functionality that essentially ties the MB status to whatever is set in Envoy. At this moment it would require a Prime erase, then for you to disable MB in Envoy and begin onboarding Prime again as a ‘manual’ user. During this process you could recover from the existing keycards and have the whole thing complete in <15 minutes, but if you don’t feel comfortable doing so, I’d advise you to wait for an update.
We’ve already started work to make it more independent in the next major KeyOS release v1.3.0, where you’ll be able to freely toggle either MB off independently.