Good point, which I have been trying to work out. Apart from the fact that I have not been in a darkroom since 1989, the only ones I am aware of are some in Central London and one in Rickmansworth off the M25 (easier to get to but closed since the start of the pandemic). I live in Ealing and know that the College has one, but doubt that they will let me in as a non-student (and I am chained to my desk 10-11 hours a day during the week).If you have or have access to a darkroom, learn about making a "Proper Proof." This simple "tool" will go a long way toward controlling your process. No idea how you would go about this technique via scanning and the desktop.