Well we are finally licensed! We had some serious issues one night because of some recommendations we received that included creating a second vmk for VSAN traffic.
We did have to migrate the VMKernel for VSAN off of the VDS before we were able to license the host. We may have ran into a bug while doing this step. We used the webclient to migrate the VMK with VSAN Traffic from our VDS to a VSS while in maintenance mode. Then we migrated back to the VDS and tried to delete our VSS. We received a message that we were about to delete a VSS with a VMK on it although we had already migrated the VMK back to the VDS. We proceeded with the deletion but the host had no VSAN access when we brought it out of maintenance mode. We had to recreate the VSS and migrate the VMK back in order to regain VSAN access. Then everything was successful when we re-migrated it back to the VDS and deleted the VSS.
So the procedure that worked best for us in the end was to:
1. Migrate all VMs off the host
2. Migrate the VSAN Traffic VMK to a VSS that uses a Physical Adapter connected to the same Layer 2 network as the VDS
3. Remove the host from the VDS
4. License the Host
5. Re-add the host to the VDS
6. Migrate the VSAN Traffic VMK back to the VDS
7. Migrate all the VMs back
We did migrate the VMK for VSAN Traffic while both in and out maintenance mode. We did not experience any difference although maintenance mode may be best practice.