I believe that the starter is just buffer and halide to insure that the startup pH is what is to be expected in a seasoned tank. The problem is that in the range of about 5.5 - 6.7 pH is not critical. Of course this depends on Bleach. Bleach III is lower in pH than the older bleaches. (Bleach III is greenish and earlier bleaches are reddish)
AFAIK, there is no significant effect given to a bleach by the starter as long as the silver is bleached at the right pH. Going to acidic will destroy dyes and going too acidic will stop bleaching action. As soon as bleaching starts, it is "seasoned" in the sense that the film being bleached rapidly changes the environment anyhow.