I have enlarged hundreds of photo for people. Artists and Photographer. Most od them use box speed. The results are aweful. So much trying to get a decent print. I lot of people do not change their exposure or development with thought according to the lighting situations.
Basically I use a similar method used by Phil Davis in exposing film under an enlarger. Develop five or more testa at differnt times and plot them. I use a more contrasty "standard" to Phil Davis since I find his reults to soft to be practical.
My aim is to fit my negatives to a Paper contrast of 1.05. As mentioned I usually increase my devolpment because of the use of unsharp masks. If I desire I do change my exposure according to what I want or need.
Have to go dinner is being served. I will get back to this later.