I don't use a bow holder. Once I'm up in the tree I slip my hand into the tight bow sling I have and keep it there until it's time to climb down at night. I'm always no more than a few seconds from shooting an arrow. The deer in my area have a habit of just "appearing". You don't hear them, you don't see them, you just look up and there's a deer.
My bow is light enough where keeping it attached to my wrist by the bow sling isn't that uncomfortable. I've even taken a nap in the stand with it on.