I had the same reservations Michael, and that's why I posed the question to Ron. I think most of us would agree that Ron's knowledge of photochemisty would surpass that of most of us. However, I called Formulary last year, and asked about the affect of TF5 on Azo papers developed in Amidol. The person who answered was unable to provide an answer, and until the affect was known, suggested that it would be best to eschew the use of TF5 when using such materials. Perhaps Ron would like to chime in again?
I wonder about the wash times.....Ilford's permanence sequence using their Rapid Fix does not indicate that the wash time with FB papers needs to be inordinately long. Is Ilford Rapid Fix acidic?