I know of a company up in NE Ohio that has at least three XPT repeaters. They all serve the same entity (a transit authority). They are somehow linked, but DSDPlus doesn't currently reveal anything to suggest that they are linked.
Either (a) DSDPlus can't display such information because it hasn't been programmed to detect and process linking messages or (b) XPT linking messages perhaps only travel across the backhaul links.
I'd think though that linking information would be passed over the air -- I would think the radios should be able to roam freely between the multiple locations without anybody having to turn a dial / select a different repeater.
I know the same talkgroups are in use on all three repeaters.
Maybe I need to capture a large raw audio file from one of the sites when there is significant activity going on and send it in, with the hope that if the linking information is being sent over the air DSDPlus could be modified to display the relevant info.
Mike