Kind of a mess because I have other groupings going on here, but in the WLAN config, I have two groups of interest, the "Default" group and the "Fuze no 2.4" group. "Fuze" is the SSID where I do not want 2.4 enabled. "Default" includes the SSID where I want 2.4 disabled, and "Fuze no 2.4" does not include the Fuze SSID:
There's not much to set in these groups, just really a list of WLANs.
In the "APs" section, that's where we do things and since I already have a general "no 2.4GHz at all" group which has some APs in it to avoid overlap and such, these two groups are the only real configs of interest here:
Every AP (ignore my "guest group") is in either in the "disable 2.4GHz" group, so it wasn't enabled for the Fuze SSID in the first place, and the "Fuze Disable 2.4GHz" group contains the rest of the APs. In the config for the "Fuze Disable 2.4GHz" AP group, I have the "Fuze no 2.4" WLAN group selected, so those APs only have the SSIDs in the "Fuze no 2.4" group enabled.
Make sense? It's kind of backwards. This whole system is kind of a pain and not very intuitive.