In my case, it will be interesting to be able to schedule periodic or "one shot" maintenance windows per VM:
Periodic DB reorganization/reindexing. Some applications reindex all DBs once a week/month. That's a lot of I/O and data modified = huge snapshots. It is not a good idea to create or remove a snapshot while reindexing 100GB tables.
Periodic data export/import jobs. For instance, export production DB to a folder, import in test. Again, sometimes it is 800GB or more.
And also, punctual maintenance. Sometimes it is needed to fix DBs, migrate data, update applications, etc. which may involve a lot of modified blocks and/or IO. The SAP team might work during the night, but I prefer to go sleep and not to care about enabling/disabling backups by hand
And there is also vmware infrastructure maintenance/patching which might require to disable all activities in a specific vCenter/host server.