I talked to tech support and found out where everything was going wrong. The HeosDrive is basically 4 separate Heos Amps in a box. So each line input is hardwired to a zone, then digitized on the network to share in other zones. Also, grouping zones does something that causes the delay and elan automatically groups the zones when you pick the same source in more than one zone.
Civil War reenactment is LARPing for people with no imagination.