A band-aid it is: shorten the control pressure cable by one turn (quicker shiffs) and tighten the modulator pressure one turn (clockwise)and get a different tech for your MB trans problems.
Modulator pressure is most important to shift pressure (how hard the shift is).
Unfortunately the 1981-82 transmissions had a number of areas that were modified in production by 1983-84. These included clutch pack end play, second gear band, and and 1st gear band servo piston (releases on application of 4th gear clutch pack and leaks caused reduced pressures).
The reason for these modifications were basically two related problems: #1 second gear hit too hard and #2 4th gear would flare, especially if one tried to get a decent second gear shift by modulator adjustment.
As it turns out the tranny will shift like that indefinely, so if you can get your band-aid to work good enough just live with it til you are in a better position to fix it. Then get someone who knows what mods to do or it will still shift the same after its rebuilt, possibly.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician