The cleaner way to do it (but more time-consuming) would be to Attach one to the other in Editable Poly, then delete the overlapping triangles, then use Bridge to fill in the gap.
With Javascript it seems the only way to keep running a script when working underphotoshop is using Bridge.... :( Then you will need to start it if you want the autosave script ...
If you liked those physics based puzzles you might be interested to look into the games that probably pioneered this style of gameplay, the bridge games available here.
you can, however, navigate to the parent material (if bridge makes them... it might not for weird copyright reasons) from the instance parameter panel.