Hey Shadius,As others have mentioned, there isn't a way to download configs from your devices. I'm not sure what the end goal is, but you can 'save' a switch config by making use of templates/switch profiles. Check out the following doc for more info...

As mentioned, I wouldn't worry about it. If you want to be absolutely certain that there isn't another DHCP server on your LAN, run a PCAP on the LAN port and look for any DHCP activity (filter is 'bootp')

Do you have any type of monitoring on the switch/uplinks? I'm thinking the APs briefly lose upstream connection, and switch to mesh. A power cycle will then be required to force it back to GW mode.Also, is your firmware up to date?

Do you know if there is a client cap in the AP software?

Yes, all of the APs will need to have BLE support. That info should be in the APs datasheet.