ESP8266 Community Forum

How well can ESP-NOW transmit on different channels while connected to WiFi as a STA? If trying to find/discover devices that may be on a different channel, would it have to disconnect() from the AP then de-init() / re-init() or is it possible for it to "under the hood" / automagically switch a different channel just long enough to send a message then return back to the AP channel to maintain connection with the AP?

Answering myself with what I found on google,

You could send out a 'ping' or keepalive packet out from one side every now and then, e.g. every second or so. If the other side doesn't see the 'ping' packets, shut down STA mode if needed (so you can change channels) and listen on each WiFi channel for a second or two, see if the other side migrated there.