As for the age times, those are the times since an ADS-B sentence was last successfully heard for a given aircraft. Note that keyword "successfully"; if there is a bit error in a received sentence causing a checksum failure, the sentence will be discarded and not counted as received. Distant aircraft will probably have higher error rates, causing slower updates.
The View>Aircraft list/table shows many dozens of a/c updating at intervals of 0-1 second. I'm fairly sure that it's not due to dropped or discarded packets. My point was about the somewhat random intervals between screen refreshes, sometimes a few seconds and other times over 30 seconds. I don't know what causes that randomization. As I said, it doesn't appear to be processor issues, as the list updates seemingly at 1 second intervals. Maybe it's the map refresh that gets bogged down? The refresh certainly takes a good fraction of a second, at least for this pc, so maybe there's just so many calls to rewrite the screen that something can't respond that quickly? The dashboard pseudo-LED for ADS-B RF is always green with short flashes of black. The ADS-B receiver is an RPi 4 so it can feed data pretty rapidly. Using a browser interface, I'm getting 400-600 decoded messages per second.
Anyway, I'll be out in the middle of nowhere over the weekend and will see how the refresh behaves in a less intense receiving environment.
Cheers and 73 - Jon N7UV