Thanks for all the responses. I might be headed in the wrong direction with this idea. For my current project, I'm shooting indoors using strong window light. Even so, my exposures (f16 using Ilford MG paper) are in the 45 to 90 second range. I know from experience that using a green filter outdoors costs me four to five stops. This is perfect in bright outdoor conditions. Indoors, I could be exposing for quite a long time.
I've used grade 2 paper in the past and might have to restock.
I'm already preflashing. I get good enough shadow detail, but now the highlights seem to blow rather fast. I don't know if I can blame that on preflashing though.
I'm interested now in the idea of diluting my developer to control contrast. I use Ilford PQ at the recommended dilution and time (1+9, I think, for 60 seconds).