For clarification, papers have exposure scales (ES), not density range. In practice what we want to do is match the DR of a negtive to the ES of the paper.
I am surprised how close your times for FP4+ with brush develoment are to my times with rotary processing for the same DR. For example, using the SBR method, when shooting for a DR of 1.6 I need the following times wiht the 2;2:100 dilution oif Pyrocat-HD at 70F.
SBR 10 5:00 minutes
SBR 9 6:30 minutes
SBR 8 9:15 minutes
SBR 7 11:00 minutes
SBR 6 14:00 minutes
SBR 5 19:00 minutes
These are the times I use with FP4+ for kallitype and palladium negatives. I am really surprised that you need a negative with this much density range for AZ0. I wonder if this isthe experience of other AZO printers?