yes.. I had the same question. Very specific intrusion and suddenly in few places I was stuck.

I'm wondering why effective film speed is so low in your test. Underexposure? Massive Dev Chart suggests 13 minutes as standard http://www.digitaltruth.com/devchart...ch&TempUnits=C based on your test N dev time is slightly more that 8 minutes.
Maybe in that case dev times should be 5.5 8 11 16 22 minutes ?