About the acid stop with TF4 -
The first time I used TF4, it was with Pyrocat HD and, I think, FP4, 2 1/4. I forgot about the recommended water stop and used a very weak acetic acid stop (something like a drop or two in 500cc water). I saw some strange artifacts in uniform areas of the negative (like sky areas) and called Formulary about it (I thought at the time that it was the Pyrocat). I was told in no uncertain terms that any acid in the stop was not good for the TF4. I replaced the fix, have adhered to the water only stop bath advice (I use a minute of running water in a tray for fiber prints - after a 15 second dip in a deep tray of water), and had no problems since.
I hear what some of you experts are saying about the buffering of TF4, and recently, as described in a thread I put out a few weeks ago, I too, had some yellow edges in 16x20 Ilford MG IV VC, first time ever.