Currently the only way to change the storage domain of the hosted-engine deployment is to run the backup and restore procedure. As it happens quite often that Storage is decommissioned and for that Storage Domains need to be migrated, the missing support for Hosted Engine and the quite complex procedure for this needs to be adressed. So the usecase is: As an admin I want to be able to storage migrate my Hosted Engine storage from one Storage Domain to another easily and without longer outages.
closing deferred, we have no capacity for handling this for now.