Not much effort at all, and it /is/ easy & non-disruptive to the rest of the network. I spent some time messing with it yesterday.
When in "repeater" mode on the XT8 running latest stable gnuton/merlin the "Wireless" tab on the left is absent. The "General" and "Professional" tab content can be reached manually via the browser location bar, but the layout / content is very abbreviated and does not include transmit power adjustment. So back to AP mode, reduce transmit powers for the two client-facing radios [an aside: it's somewhat irksome that the adjustment requires a complete router reboot (couldn't just unload / load the modules?); /very/ irksome that it must be done sequentially rather than queuing and combining them into a single reboot].
Switch back to "repeater" mode and the power levels have remained at a reduced setting and everything appears to work as expected.
The power levels also remained as set when switching to "Media Bridge" mode as well as back to AP mode. I did not check "Router" or "AiMesh Node" modes.
So it's /somewhat/ tedious to make the power adjustment, but in all the flip-flopping around of just the one device, the rest of the network remained in fully-functional service, with no interruptions.
There is no need to bring down or even disrupt the rest of the network while thus adjusting the one device. And operating just the one unit in a different mode will not degrade /any/ of the AiMesh value present in the rest of the system.
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Okay, I spent a couple hours today, off and on, toying with this. I'm going to describe as tersely as I can what I have and what I did.
A pair of V1 XT8s operating in router / AP mode for the very real within-network performance increase over what can be achieved under AiMesh. On a very good sale price picked up a GT-AX6000 to use as the router so as to feed the XT8 AP with 2.5 Gb ethernet. Remaining XT8 used variously but mostly with 2.4 and 5-1 turned off, associating with only one computer on 5-2 (for very real performance boost). All running their latest stable gnuton/merlin firmware.
I reconfigured the spare XT8 as an AiMesh node, first to the other (AP) XT8 via 5-2 @160MHz, then to the GT (via 5-1 since that's where I have the GT operating). In-network performance plumeted, as expected, as well near total lack of control of the "node", as expected. Setting nvram variables in an attempt to decrease transmit levels followed by a reboot for them to take effect avails nothing. The radios are set up entirely by the controller each time the node boots up and becomes meshed. The only way to control /any/ radio transmit levels is entirely global for the mesh via the controller. This level of control and performance is drastically below that of my usual system configuration. Drastically.
I reconfigured the spare XT8 as a "repeater", once again both to each the GT router and XT AP. The first using the repeater's 5-1 radio (80MHz x 2) to the router ('cause that's the part of the band the router's assigned to - running 160MHz x 4), and via 5-2 (160MHz x 4) (one end of the house to the other one floor apart). Both worked as well as can be expected for the scheme: somewhat better than under AiMesh, but still poorly-performing within the network. There is no direct GUI access to adjust power levels in "repeater" mode. However, setting the appropriate wl?_txpower nvram variables via ssh followed by a command line "reboot" brought the unit up with the desired power levels in service.
I did all this, and more, while watching air-streamed entertainment. The only disruption to any of the network was any associated clients immediately and painlessly hopping over to another broadcaster.
Unless you're carrying an isolated guest network to the outbuilding, your entire system will operate just as it does now, with seamless roaming, et al, throughout; AiMesh just like you like it except for the outlying router, which you will be able to /MUCH/ better control.
In my setup sans AiMesh, each of the three web interfaces show ALL system-connected clients, indicated by wireless if directly associated or by wired if associated elsewhere.
Remove the one node from the mesh via the controller's GUI. When it comes back up (you will have to isolate it from any other XT8 broadcasting or it'll become a mesh node again), select operation as "repeater" and select the /particular/ broadcaster/band to use as its feed.
Fill in the exact same SSID(s) and passphrases you're currently using, and wait for it to reboot.
Once it's up, log into its GUI and enable ssh. Then ssh into it and issue the following two commands, substituting your client-use SSID for the example. I use two SSIDs, "SomethingNet" for 2.4 and 5 (or 5-1) operating as if "smartcast" though I have that disabled, and "SomethingNetHi" for the 5-2 radios.
Bash:
nvram show 2>/dev/null | grep 'txpower\|SomethingNet\(Hi\)\?$'
will list the radios and their ssids something like this:
Code:
# nvram show 2>/dev/null | grep 'txpower\|SomethingNet\(Hi\)\?$'
wl0_ssid=SomethingNet
wl0_txpower=100
wl1_ssid=SomethingNet
wl1_txpower=100
wl2_ssid=SomethingNetHi
wl2_txpower=100
wl_txpower=100
wlc_ssid=SomethingNetHi
Assuming you're using the 5-2 as your "backhaul" leave the "wl2_" stuff alone. wl0_* will be 2.4GHz and wl1_* will be 5-1.
Then
Bash:
nvram set wl0_txpower=50
nvram set wl1_txpower=50
reboot
"50" and "88" will be your two most likely values to use. You can swap them in at any time for testing purposes.
This will decrease the transmit power of the XT8 in the outbuilding and should keep it out of the kids' rooms yet still work well-enough in that building and it's immediate surroundings.
The option offered a few posts up to prevent roaming will not be satisfying if it even works.
At /any/ time you may log into the XT8's GUI and tell it you want it to become an AiMesh node. It will, after several minutes, perhaps with a little interaction on the router if necessary, show back up just exactly like it was before you started. The rest of your network will remain fully intact and operational throughout the process, either direction.