SCVMM (VMM) & S2D should support cross-cluster migration of highly available VMs
Migrations of highly-available VMs from one cluster to another while using S2D and SOFS as a storage solution (NOT hyper-converged) should be supported by VMM.
VMM has built-in functionality to allow migration of a VM from one cluster to another.
This does NOT work with HA VMs when your storage solution is SOFS on S2D. The VM will be placed in pause-critical, effectively a failed migration.
I believe this is a shortcoming on the part of Failover Clustering not properly handling storage communication, but not sure as this action isn't able to be automated outside VMM.
Note that this issue persists in 2019 with VMM 1807.