Just a comment?
All transmissions get a terrific BANG on the shift (slightly reduced by a loose converter), which beats up the friction material, loads the anchor points, etc. and also shocks the entire chassis. Oh, that's why the car jumps, tries to climb a tree, blah, on the 1-2!
Has anyone dealt with this?
My Lexus DD has factory spark retard to kill some power on the shift using a signal from the shift solenoid. Helps, not adjustable.
An MSD box could do this if it could "see" pressure applied/released on gear change inside a 727 valve body, if some clever person could find a place to tap in? On the linkage might work with manual VB but you'd have to estimate and program the retard time in .001 seconds, etc.