Ah, well, that's kind of a conundrum; if you want to control the LEDs while the cover is closed, then really, the app should remain running while the cover is closed, right? I'm really not sure exactly how to both ignore the cover state and use the cover state at the same time. I could, for example, use the rule "If I'm ignoring the cover, but at some point the state goes from open to closed, I'll quit the app", it might work for your
I was envisaging a single slider like the volume control in status menu with % value next to it (or even across it) and Xms on - Yms off under it as calculated values. Not only would it look cool but it would also allow for dynamic limiting of the duty cycle and/or longest on timer depending on the brightness (which I incidentally also envision as a slider). But I will let Copernicus decide that