That is slick. I have come to really like that guy and some of his podcasts. One of his most recent, maybe 2-3 episodes ago of his podcast he had a professional arborist on there talking about ropes, climbing safety and what not and it was very elucidating! i am planning to change a few things up after listening to that and cross-checking with a few arborist guys I know.
I think this little slick mod could be done without the rubber inner tube handle, maybe a strong rubberband of something like that.