isUnheardOnCurrentLora

True when the radio does not report having heard this node over RF on the LoRa configuration in force now, and it is not an viaMqtt node.

This is not a claim that the node was ever heard over RF. heard_on_current_lora is a single bool, and the radio does not expose its "heard over RF at least once" bit separately, so a node heard under different settings and a node never heard at all (one added as a shared contact, say) are indistinguishable here. Both read true. Callers that must not act on the second case need another signal - the removal offer relies on favourites, which is what firmware marks a contact.

viaMqtt nodes are excluded because they arrive over the internet rather than over our own radio, so the radio never marks them heard over RF and heardOnCurrentLora is false for them permanently - not because a setting changed. Presenting those as unreachable would badge every node on an MQTT-uplinked mesh and offer it for removal, and removing one is pointless because it returns on the next uplinked packet.