The reason I started this effort was mostly for the "Fun" of converting to a Parent / Child app. I happen to have code templates for it that has been crying to be used.
Next was the desire to add in the green status hint... I thought that would be fun too.
The result is: an alternative that shouldn't replace ALL of MFornander's Auto Off deployment. If you have only ONE instance, I can't see why eating two lines on the Apps list would be "better."
The scheduling for Auto Off uses: runEvery1Minute()
The scheduling for Auto_Off uses: runIn(delay)
The documentation for runIn() advises of an option for "Misfire":
misfire - If set to "ignore" then the scheduler will simply try to fire it as soon as it can. NOTE: if a scheduler uses this instruction, and it has missed several of its scheduled firings, then several rapid firings may occur as the scheduler attempts to catch back up to where it would have been.
Neither MFornander nor I use that 'feature'. I think it's because of the Note. "rapid firings" scares me. Ok, not exactly scare, but applies caution. In other words, I think both versions of the App would react the same to your scenario.
The second question is more about Hub time and it's impact on scheduling. If your Hub, which keeps time by polling an NTP server, drifts because there's no access to a NTP server, then the scheduling would be effected too. I'd advise pulling NTP inside your house via an always on computer that has an internal RTC (Real Time Clock). In this way, the RTC is 'bumped' by periodic polling of an Internet NTP server to maintain a very high accuracy and low drift. You then use the community's NTP driver to sync Hubitat to that NTP server inside your home.