What load are you at now? Don't think its that bad. I am assuming you have a cluster controller by OpsMan,so are you using SDS to share forms like Feature access codes and such? It looks to me like you only need to sync Ops and cleanup. Setup sharing in you haven't already,share user profile, run the migration precheck and cleanup. Final sync in Ops. Delete any schedules in Opsman.
I don't know thats what I read. I have only do a non Ops cluster. Going from a single 3300 R9 to MCD 4 cluster without OpsMan, then upgrading to 4.1 Most of the process appears the same except the involvement of OpsMan.