Here would be my use case:
For example, I have 60 HVAC zones that all have the same points - space temp, setpoint, damper position, etc. I store all these points in tables in the strategy. So if I want the space temperature from zone 10, ZoneSpaceTemp would get me that data. This allows for a single chart to iterate through all the zones to perform the operating logic. Works beautifully.
Now when it comes to display, I have two choices:
Create a window for one zone and then copy it for all the others and hope the customer never requests a change and that I don't make any mistakes on the source window so I don't have to fix 60 separate windows or delete them all and start the copy process all over again. (<- So this isn't much of a choice)
Create one window and have it pull data from "Display variables" in the strategy. So the user selects a zone from a floorplan graphic, that will store a display index variable in the strategy with the zone number that was selected. I then have a chart that has logic that moves the requested zone variables from the tables into display variables like this: DisplayZoneSpaceTemp = ZoneSpaceTemp[DisplayIndex];
This works just fine, as long as only one operator is viewing the zones, since any operator can change the DisplayIndex. To work around this, I have to create multiple DisplayIndex's for each workstation and have a custom PAC Display HMI for each workstation that is hard coded to that DisplayIndex - no fun when I need to do updates to the HMI.
What I would like is to have a variable that is local to PAC Display that I can use as a DisplayIndex to pull the ZoneSpaceTemp directly. This would eliminate having to have a display chart in the strategy and also allow multiple users to use display and see different zones at the same time without doing a bunch of extra work and creating a maintenance nightmare.
If this was something that was available in Groov, then I would consider looking at it again, but currently I do not use Groov.