Sounds efficient. I hadn't seen those. Do you carry your saddle (to your spot) in it too?
I also don't like stuff pulling on my saddle, but have MOLLE all over my packs for dump pouches, and I usually climb with my pack on. One is sling style, so it's easy to get to if I want.
For my other pack, maybe a dump pouch with a single long string loop or strap loop that just stows in a sewn on pocket would be the ticket. Sort of a smallish satchel that I could employ at the tree.
Then again, I usually use the hang sticks from steps as I climb method so I'm not probably going to need access to straps during the climb other than for the stand.
I do pack in my saddle, so I like the idea of consolidating it with all climbing essentials. Thanks for sharing, gets me thinking about how to dial in my .5 setup.