Allow configurable cellular connectivity alerts

Cellular connections are intended to only be backups. I don't want to get an email that the connection has gone down for 2 minutes. I'd like to be able to adjust sensitivity on that alert to alert me only if the cellular connection has gone down for an extended period.
Example: After a MX firmware upgrade my UML290 modem needed to have it's firmware upgraded to connect. Since I didn't have an alert for this setting I went a few months without knowing that my cellular connection wasn't going to be there if I needed it.