The company I worked for in 1989 had three hand-me-down MicroVax II from the US parent.
They were originally a PDP11/73 box, which had been converted. They ran VMS 5.5-2, all had DEQNA, with no problems that I remember. They were just networked, it wasn't a cluster. The DEQNA may have been *unsupported* on 5.5, but it seeded to work OK. I still have one system, and bits of the others. Failing ESDI drives put them to the back of the garage. I do have a replacement ESDI drive, and a Q-bus SCSI controller, so when i get time (ha!), I'll resurrect it. Regards, Graham