Device Alias is a proprietary feature of MDS. I believe that you can configure Device Alias on the MDS even if some VSANs are in interop mode, but when you perform zoning on the interop VSAN, I would recommend using the device PWWN and not the Device Alias. It may work since Device Alias is associated to 1 PWWN, and it is not passed with the zone database. Device Alias database is passed via Cisco Fabric Services (CFS) which again is a Cisco proprietary feature.