Let me add to the previous message that stand develoment is more appropriate for printing with reglar silver gelatin papers than with AZO. I doubt very much that you would be able to get a high enough CI for AZO using a 3:3:600 dilution of Pyrocat-HD with stand development.

I am really not sure what you hoped to achieve with this extreme dilution, assuming the final objective is AZO printing. My tests would indicate that you could handle an SBR of 9 with the 2:2:100 dilution of Pyrocat-HD with a development time of around 7-8 minutes. This should give you a negative with a DR of about 1.3 (Visual) or 1.6 (Blue) that would be just about right for AZO.