You should have some considerations, why could h depend on L and N. Otherwise, for broader generality you should also consider dependence on Moon phase, which btw is easier to know for the device than L and N.
I don't know how to react to your post. It looks half-trollish, half-jokish. For a programmer the dependence between those 3 parameters is so obvious that it's impossible to explain to someone else (as most of obvious things).
OK, maybe you'll try to explain. Let's first consider dependency on L. So PoW difficulty to generate an envelope depends on current number of tips. And the device probably doesn't even know that number. Why does it depend? In Bitcoin and its clones for example difficulty doesn't depend on tps rate or whatever parameter that could be comparable to the number of tips in the DAG.