I have to say, I am impressed with the effectiveness of your trap idea. It gives me great ideas for the copperhead study that I am currently working on. These are terribly misunderstood and awesome creatures!
The fact you are catching them in your coop is kind of bothersome. If they can't get in...they're not a problem. Collect your eggs daily and your chickens should be safely roosted above them (copperheads). Though it is unlikely that the copperheads would even target grown chickens. Very small chicks would be my only concern with them.
This trap is an ingenious tool to relocate them short distances from the property to areas where they're less likely to be a problem.
My study area so far has produced zero copperheads! It seems that every local that I talk to in the area, has killed every snake they see. It is kind of disheartening really. This is why I have been a bit more proactive with the snakes lately. You would not believe the rodent populations in this area either, definitely a direct correlation there!
I have plenty of snakes around my home, no snake problems, though I do anticipate a rare problem, it has not happened...ever!
As for the raccoons and foxes...they have really been a problem. I have no qualms about eliminating them when necessary!
Sorry if I offend anyone with these posts, I'm just trying to spread some facts around. We're all capable of learning and changing ways of thinking...I did!