Hi Domesenn_
From my understanding and engagement with Support, there is no currently supported way to update an existing Service Engine. A new will need to be created after the resource allocation is updated on the SE Group.
Is manually updating the Service Engine resources supported as I have asked this before as well and it was mentioned as it is not supported method.
Migrating to a new Service Engine will be less disruptive as updating via vCenter will require downtime.
Sulaiman