@Eric_Inovelli I have 30 Hue on one network (with ~18 blue series controlling them) and 25 Hue on the other (w/ ~10 blue series).
The most I have bound on a single switch is a group of 6, but I haven’t noticed any correlation in my testing between the # bound to a single switch vs bind reliability. When it works, it works BEAUTIFULLY- immediate response. The broken behavior tends to happen when pressing multiple switches quickly right after each other e.g. the use case of turning off all of the basement lights from a 3 gang bank of switches one after another: I can pretty reliably get at least one of the 3 bindings to fail when doing this. I can also reliably get the binding to fail by quickly toggling a single switch on and off a few times within a few seconds.
I’m not a zigbee expert by any means, but I can’t help but be suspicious of all the broadcast messages the switch sends to all the nodes in the network when the physical switch is pressed. Note that I can toggle on and off my GE zigbee switch bound to a Hue bulb as fast as I can press it and the binding stays reliable (it’s only sending ~4 messages per tap vs the 60+ messages when tapping the Blue series).
Again, I can’t stress enough zigbee is new to me and my “conclusions” about the causes of my poor reliability are pure speculation based on the evidence I’m seeing through my sniffing dongle: I could be way off base here. 