I’ve also had smooth sailing for over 36 hours. The monitor job did have to restart the polling scheduler once or twice, but everything got going again like it’s supposed to. I think it’s a combination of the ST environment being more stable and finally finding a smooth set of code.
I made a tiny update today to my code to make the cron schedules run on odd seconds rather than always on “0” of every X minute. The idea is that most smartApps have probably been set by default to run on the 0 second, which means it’s probably the most crowded time of all to run something. It’s discussed more here: Scheduler and Polling quits after some minutes, hours, or days - #35 by copyninja
Anyway, feel free to try that to further stabilize things. As long as you’re not on the V4 code, you won’t need to uninstall/reinstall since it’s such a small update. You will want to reinitialize though (just click through the app setup once to get it started with the new schedule interval)