Difference in successfull reception between gps and normal forwarder

I haven't had a lot of spare time lately, so not sure what the current status is (also looking at the Slack conversations).
Will influxdb be replaced by mongo?
Which packets will need to be inspected (next to the status messages)?
Currently a gateway is noted as 'down' when no status update was received in the last 2 hours. One status update per hour (or half hour, or 10 minutes) should be OK, right?
Alternatively, we could look at the last packet (any packet), is that what you're suggesting?