I recently presoaked some Efke R100, the first film I've presoaked in 20+ years, because the maker recommends it. I can see why - the anti-halation dye *immediately* discolored the water. It's far less tenacious than dyes on other films.
Then it occurred to me to try presoaking before development in Diafine. Since Diafine is reused repeatedly it can accumulate a lot of dye. I figured that presoaking might minimize that problem.
The first film I had available was TMY, notorious for retaining a tint after processing. Presoaking in our fairly alkaline tap water (from a rural well) didn't remove a significant amount of dye. It was very slightly tinted, but nothing like the pour-off from Efke R100.
I can see the advantage to presoaking for very short development times - 5 minutes or less - or for films *proven* to benefit from the practice.
But I don't plan to change my procedure of simply starting rollfilm development from dry.