Could there be some other reason for your hub crashing, not just the "heavy debug logging"? My hub runs with tons of logging constantly, running both my house and doing dev work on it, and I've never seen a problem related to logging volume.
It's always good to update to most recent release, which currently is 18.104.22.168, to see if your issue persists. As @bravenel suggested, verbose logging is unlikely the reason for a hub to slow down, and if you enabled logging for apps or drivers, rebooting the hub wouldn't automatically disable the extra logging. Screening the past logs may reveal what actually caused the problem.