Doing so further tesint on my setup at the risk of messing something up, I did some testing.
I'm not sure if what your asking for, disabling the radio is not the same as disabiling 802.11ax
Note, 802.11ax radios can transmit and receive either the 2.4 GHz or 5 GHz frequency bands.
Even with SmartConnect you can disable a radio on a node but not 802.11ax. Here's the router with 2 nodes, with the management details on a node under AImesh within the GUi showing that the 2.4Ghz radio can be disabled without messing with the 5Ghz radio under SmartConnect. There's not a seprate option for 802.11ax on the node in Aimesh and certainly disabling the radio per node/router disables 802.11ax but also the radio. Turning off SmartConnect you can disable 802.11ax per radio without disabling the radio per node/router. The trick is leaving the radios on, disabling SmartConnect, and disabling 802.11ax per radio on the router which goes to the node under Aimesh.
That said, I did turn off SmartConnect and was able to independently configue this setting per radio but only after disabling SmartConnect.
This setting under Wireless General you can disable per radio (2.4Ghz or 5Ghz), once SmartConect is off you'll be able to turn off 802.11ax per radio.
Turning off the radio is separate from disabling 802.11ax. Disabling 802.11ax at the node but not the router, not sure how that would work, but from the GUI it can't be done. Instead you likely need to SSH into the node and turn off the NVRAM seeting for 802.11ax for 2.4Ghz. Again not the same as turning off the radio with you can do from managing the node as you've done.
Still not sure what you want. So is it that you want to disable the 2.4Ghz radio (which effectively kills 802.11ax for 2.4Ghz) per router/node or is it that you just want to disable 802.11ax for 2.4Ghz leaving the radio enabled for bother router and node. You can easily disable the radio on both the router and node independently. One can also disable 802.11ax for each radio after disabling SmartConnect, which I suspect if disabled on the router also disables it on the node. What's not so simple is just disabling 802.11ax on the Aimesh node but not the Router regaurdless of the radio.
But....
Your other option is not using Aimesh and running the node in AP mode, where you can confiure all the settings independently, choosing to disable 802.11ax per frequency per Node/Router within each devices GUI without SmartConnect. A little more involved version not for the faint of heart, is to find the NVRAM setting on the node for 802.11ax on the 2.4 Ghz radio and changing it to disables it, commit and reboot but that's a more complicated manual effort.
You got options, maybe not the ones you wanted, but you have them depending what you want to disable 2.4Ghz, 802.11ax, Aimesh or Router/Node(AP) all of them or some mix of the four
