Azure VMs with local SSDs (Lsv2-series) can be used for high throughput storage. But typically they are combined with a different VM type used for storage node(s) or quorum node(s).
Availability Set is used for better fault isolation in regions that do not have Availability Zones.
Combining Lsv2-series VMs with other VM types in the same Availability Set is not currently supported by Azure. An attempt to do so will result in an error like this:
Enable use of Availability Zones instead of Availability Set if the target region supports Availability Zones.
Use a different region that support Availability Zones.
Use Lsv2-series VMs for all nodes of the cluster. Contact FlashGrid support for assistance.