Ilford Rapid Fixer, how many rolls from 500ml

Negative are hanging to dry and look good. Fresh fixer cleared the film and a ten minute running water wash removed and tint from the anti-halation backing. I'm going with the 12 rolls per bottle plan.

Ealy morning sunlight was pretty strong and adjusting to a new process is always a learning experience:
M4-2, Voigtlander 35 1.4 Nokton Classic SC V2, Tri-X @ ISO 320, Ilfotec HC 1+31

Here are a few more from the second roll. It does control the grain better but the negatives look flat next to the ones developed in Rodinal.
M4-2, Voigtlander 35 1.4 Nokton Classic SC V2, Tri-X @ ISO 320, Ilfotec HC 1+31: