I've been playing with a subpanel for some of my VIs with LV 8.5 - I have some VIs that communicate with databinding controls linked to shared variables. These work very well when I use them in standalone mode (directly opening them). However, when I invoke them in a subpanel, these controls are no longer bound to the shared variables.
Also, I tried making a VI that connects to one of the the shared variables with ye olde datasocket VIs - again it works fine when I directly invoke it - but fails when I invoke it from a subpanel. All I get is default values for the data type (0.0 for doubles).