Crawley's FX6a works well with paper but you'd need to play around with the Thiosulphate level (70-125g)and perhaps add bromide or benzotriazole, additional Hydroquinone increases the bcontrast as does lowering the Thiosulphate
Hydroquinone 12 gm
Phenidone 1 gm
Sodium sulphite (anhyd) 60 gm
Sodium hydroxide 10 gm
Sodium thiosulphate 90 gm
Water to 1000 cc
I did a lot of work on Monobaths commercially in the late 1970's and we had planned to market one specifically for papers, I've got my notes somewhere in storage
My thoughts are that some pre-flashing of the papers before the camera exposure might be a better way of controlling contrast? A soft working metol developer like Ilford ID-3 diluted more than usual may also help.
A yellow filter on the camera lens would act as a low grade number filter too for multigrade.
you are right, and that is exactly what i do. iuse either a yellow filter on the taking lens ora self-madepre-exposure filterrto reduce contrast
. now i want to make a plastic daylight tank to develop the paper within a minute or two. this way, i won't need the expensive polaroid any longer.