If I am using Motions Lights app to turn off lights after, say 20 minutes, then what will happen if I turn of the lights earlier by the physical switch? Will the 20 minute internal countdown automatically cancel out? If there are 15 minutes left to turn off, but I physically turn off the lights....and then after 5 minutes turn them on again, will the 20 minute timer restart?
By default, only motion will "reset " the timer. On/off events on the bulbs themselves would not. But sending "off" to a bulb that is already off should have harmlessly zero effect. As far as the timer, just from a practical perspective, wouldn't you have to go back into the room to turn the lights on or off, thus resetting the timer with motion anyway? (And if you're not in the room, does it matter?) 
There is a way to use a switch to prevent the lights from turning off. This could be a virtual switch you use for this purpose somehow, perhaps controlled by some rule, in case that is helpful.
My scenario is, that kids/wife go to the room triggering the lights on. Sometimes, before the delayed 20 min time is up, they may go out of the room and due to habits, will just flick the physically switch off to turn off the lights manually while walking out of the room. Hence, whenever anybody comes back to the room after any time, I want the lights to just turn on again, with the 20 min delay shutdown restarted.
If the sensors generates a "motion active" event (so it's been long enough to have reset), the lights should still turn on in that case, assuming you don't use any options in the app that would prevent this.
