I once started defining the abstraction level depth of VI's, searching someones coded several subvi's deep and keeping track of the hiearchy in you mind can be difficult, depending on the developers experience. It would be possible to make a visualistion aid that make use on a 3D-like stack of semi-transparent layers of the call chain diagrams, where one can scroll back over the call chain, and with the same scroll action move back to the deeper VI of interest. If the visualized callers use a clever way of highlighting the wire(s) that is(are) selected, in example by 'wobbling' or highlighting the interrfacing wires, then such a visualization excersise can help the programmer to quickly remember to caller code context while working on a deeper level. This might empower lesser experienced developer to investigate code that normally is too complex to grasp.
Look at it of making a LabVIEW diagram show up like a 3D design, where the programmer can see and track the data flow through another dimension.
Since a 3D perspective view with semi-transparency is technical feasible, this is an unused dimension that can be used to improve the program insight to programmers.
This would not be practical for lower level vi's in respect to where one is programming (would become too complicated) but it would certainly work for higher level VI's since it then simply follows the call chain.
