I don’t see your point? I never wanted you to use the “maximum focal length” for the calulation of the reflector.
It is only needed for calculating the size of the actual hotspot in a specific distance.
Or are you talking about the problems I had before? I was trying to test the imperial calculator by inputting the measurements (converted from metric) of the Maxabeam reflector. I got a different result. It didn’t look right and the luminous flux values were off compared to the metric version.