Thanks for contacting us regarding this issues and apologies for the slight delay in getting back to you here.
I have tried to reproduce your findings but the track time is updating for me when switching zones, are you using any particular set of steps and are able to reproduce this consistently? Do you have the zone selection set up differently than we do in our Crestron Sample Code? If you have it set up differently would you be able to send us a sample of your implementation so that we can verify the behavior on our end?
As for your zone grouping question, at the current time we only support grouping from within Roon, and once the zones are grouped you can play content to both of the zones as you would for a normal single zone. We are hoping to improve this aspect in the future but I cannot comment on any specific timelines of when that will happen. Please let me know if you are able to send a sample of your zone implementation for review.