[tor-relays] uptime "algorithm"

As far as understand it is the flag HSdir given to nodes with a fast enough connection and a long enough uptime. If I keep my tor relay version always up to the current stable version I sometimes do have to restart the process. So I get a drop in my uptime and loose the HSdir flag for several days. Other nodes who don't care about versions keep the flag, despite the fact they might use older/inefficient/insecure/buggy versions. Wouldn't it be better to monitor the reason for a drop in uptime? In case at the same time a restart occurs the version increases it might be given the HSdir flag again? someone understands what I mean?