Hello. There is a bunch of RBcAPGi-5acD2 with wifi-qcom-ac firmware managed by CCR2004-16G-2S+ with "WiFi" menu.
And there is a cAPGi-5HaxD2HaxD (with wifi-qcom) ready to join the party.
I wonder, Is it possible to add it to the same controller? I would be ok to lose all ax capabilities and run the AP in ac-only mode (if it is possible).
Why wouldn't u be able to do that, all you have to do is put the cap ax's into the capsman mode and it should automatically detect the AP when plugged into the network.
The firmware should also be managed the same way except now u would have to upload it to the files of the router when upgrading them remotely its just one more file to download (wifi-qcom).
Why do u think u would have to lose the ax capabilities, you would just need to make new configuration profiles for the AX devices, and it should all work no issues.
The new /interface/wifi menu manages Wi-Fi 5 wave2 and newer interfaces, so 802.11ac devices running wifi-qcom-ac use exactly the same configuration as the 802.11ax/be devices documented under Wi-Fi 6 / 7 (802.11ax/be). This section therefore links to that reference rather than duplicating it.
And the easiest way to add a cap is by putting the cap into caps-mode: