Adding 2.4 GHz HomeKit devices to LINKSYS mesh wifi

I currently use a BT Wholehome wifi mesh network, connected via ethernet cable to a Linksys Fibre router (whose wifi signal I never connect to).

For HomeKit purposes it works very well, as I can add 2.4 GHz only accessories by turning off the 5 GHz band for 30 minutes, and then, when I've connected the accessories, I can ensure they only ever attempt to access the 2.4 GHz band using the BT Wholehome online interface page, see below...

Perfect.

But I'm looking to replace my ancient BT Wholehome mesh with a newer, faster LINKSYS one.

I've got a headache currently as I've just spent an hour having an online chat with LINKSYS support, trying to find out if I can select a wifi band device-by-device, per the illustration above. But the guy didn't seem to grasp the question...

So my question to any LINKSYS mesh and HomeKit owners is - can I force HomeKit accessories to use a particular LINKSYS mesh band, so 2.4 GHz only accessories (EVE door sensors for example) are prevented from attempting to use 5 GHz band that other HomeKit accessories, Logitech cameras for example, are happy using?

Thanks.