It could be done with Room Lighting. If you do not want motion to activate the lights do not use that as a trigger. You can use the light itself turning on to "activate" the RL instance. Then for the Turn off options you can setup two triggers, one would be motion inactive for X minutes, the other would be a timer since last activation (maybe X minutes + 2 or something) which is a backup in case lights are turned on but motion never triggers.
Thanks! I have something like this running. I used the "Don't Activate" option. If that means nothing ever happens I wonder why there is such an option. We'll see!
I am not sure if the Don't Activate will work, unless as stated the Turn off even if partially off would make it turn it off anyway, any time the motion is triggered and then times out, even if the RL was never activated to begin with. It might work, if not I know another way to do it.
This wont catch if someone turns the light on without triggering motion though, the light would never turn off. If that is even possible in your situation.