I don't see where you indicate the size of the accumulator holes in the vb
plate. While I'm not as familiar with the 700r4, I believe the principles in that link are the same and getting the pressure up with the tricks, using a stiff spring which you indicate you are, and using stock ish holes in the plate can produce tamer part throttle while delivering a much firmer shift at wot.
What size are your holes? Did you drill them bigger? Might need to get a new plate to start with a stockish size and sneak up on the size that works best.
Also, from my studies and advice from the knowledgeable, a spring in the servo is needed to not have a clunky 3-2 downshift. Is this what you are doing?