Lets say for the moment that this boy goes to the other troop and finds that he likes something that troop is doing. He comes back to your troop and suggests some things that are working for the other troop. Is this such a bad thing? The PLC could either accept the recommendations or not, right? Is it possible that the suggestions, along with the program already in place, could make your troop better?
There are times I see things at trainings, roundtables, camproees, or at other councils that I bring back to the troop. Not every idea is accepted but some are tried (insert Start, Stop, Continue here).
I have had boys from other troops come to visit us and I don't see it as spying, in fact I would hope some of our methods go back to other troops to make them better.