Hi Bruce.
My understanding is you are okay as you’re an owner already.
I would remove the service administrator role and leave it at that. I did this and have seen no issues on my subscriptions.
You can read about it here:
Where it confirms this:
The Service Administrator and the Co-Administrators have the equivalent access of users who have been assigned the Owner role (an Azure role) at the subscription scope.
So you should be okay as you are.
Hope this helps. Please mark as accepted if it did.