Hello.
I am considering/investigating changing the Zigbee channel on my Zigbee hub.
Reasons:
Any suggestions, comments, things I should look out for?
https://www.metageek.com/training/resources/zigbee-wifi-coexistence.html
do a wifi scan and see what wifi channels are being heavily utilized, and adjust your zigbee channel accordingly
Indeed, that's why I'm asking the question in the first place.
Have you done it? Anything I should look out for?
ahhh, i haven't done it but i don't see any concerns with doing it. when you change the channel, it should propagate out to the rest of your zigbee mesh and they would then operate over that new channel
+1. Changing the channel will mean that there will be a time when the new channel is propagating through the mesh. Your devices will be picked up as this happens. It may take a bit of time before all devices change over to the new channel, but it will happen eventually.
I did this once a while back. The only problem I recall is that I had Xiaomi devices on my network at the time, and they fell off rather than finding the new channel. Falling off isn't exactly uncommon for these devices in many circumstances, but I assume the change is what did it that time. 
A re-pair and I was on my way--something you could really try with any device that doesn't move on its own or that you want to move faster, I suppose (as long as you don't delete the device first, everything on the Hubitat side should be remembered; devices like bulbs or plugs that you reset will need their group membership re-established if you use group broadcasting in the Groups app).
This was at least a couple years ago, but I imagine it would be similar now--I don't think there have been any significant Zigbee changes.
I have my wifi on 1 and my Zigbee on 20 (which I assume corresponds to #6).
However, one of my neighbours has started to BLAST on 6, so I'm considering moving my wifi to 11, and my zigbee to 11 (corresponding to 1).
Are there any devices that won't go onto a different channel?
I've changed channels a few times. MOST devices will automatically move to the new channel eventually, but SOME do not and require manual intervention (hit the button/wake it up, or re-pair it).
I switched my Hubitat from Channel 21 to 15. Most devices reconnected on their own with 4-5 hours. A few needed to be reset and then re-paired.
Another thing I'm considering doing is to move my Zigbee hub to a more central location, and to try and make use of the wifi / udb otg approach. (I just happen to have a tp-link nano in stock).
However, all of my zigbee devices are meshed/linked to another hub, so I'm not sure about doing this. Any recommendations?
The last time I switched channel was so I can pair tuya sensors. The only issue I had was my old ST multis had to be re-paired.
I’m assuming not the dimmer button controllers. Every time I have changed the channel on the hub with these, they have all dropped. Otherwise, Samsung (Samjin outlets and sensors), Philips motion sensors, Iris V2, Sylvania (lights, sensors, and button controllers), Kwikset locks, and GE dimmers have all made the transition within a minute or two.
I’m on WiFi channel 2 (because my router is a wierdo) and Zigbee 19, 20, 24, and 25. Neighbors Wifi isn’t close enough to matter.
Love their motion sensors, hate the button controllers.
No button controllers at all - FTW. 
The only issue I’ve ever run into w/ changing the Zigbee channel is some older 1st gen Smartthings devices dont support channel 25 or 26. Other than that I’ve never had an issue with it.
Download the Hubitat app
