When trying to apply storage policy FSVM_Profile_DO_NOT_MODIFY to vms or file shares other than vsan file services virtual machines, it errors out with RuntimeFault.Summary
VMware vSAN 7.0.x
VMware vSAN 8.0.x
It's not supported to use FSVM_Profile_DO_NOT_MODIFY on objects other than the vSAN File Service Virtual Machines themselves that are running on each individual host.
The reason being is that vSAN File Service Virtual Machines need their own dedicated RAID 0 Storage Policy.
For further information on the topic:
https://www.yellow-bricks.com/2020/04/15/vsan-file-services-considerations/
Quote from said resource:
The FS VM has its own policy (FSVM_Profile_DO_NOT_MODIFY), which should not be modified!
The appliance is not protected across hosts, it is RAID-0 as resiliency is handled by the container layer!