I saw this idea and it only had one vote so I doubt it was ever implemented. Turn off Notifications for Specific Networks
We have a similar issue that a customer has a MESH AP that we have asked them to cable because signal is not enough but they do not really care and live with it. We unfortunately have to live with it notifying us of up and down. Would be happy to eliminate just the account, site or device but that is not possible that I have found.