Valve lift question

Which is why you will have to measure everything if you are trying to figure clearance. Push rod length will matter also, as it will change the ratio. In Marcos example the .0225 loss would be true with a 1.5 rocker at any cam lift if the pushrod loses .015. The rocker arm will always be 1.5.
Obviously this question is subjective and too full of variables. Even if I had an exact answer, how much of that is even relevant one the engine is running? Thermodynamics and material deflection will most definitely cause some changes. This really has little relevance to my build. My math is sound, I have a machinist I trust and this is a fairly low compression street engine. As I said, thus is just hypothetical.
Thanks