A lot of money for an adjustment, but, the adjustment would be inside the valve body or in the endplay of the reverse clutch pack. If the clutch pack has too much endplay then it takes that muchlonger to fill the drum and move the necessary distance.
I always get a chuckle at the MB service bulletins that accompanied the early development of the 722.3 tranmissions. They had left the endplay much to loose on all the early trannies and the bulletin said to just adjust this play. All you have to do is completely disassemble the tranny and measure the play and change the steel discs to thicker ones. Simple adjustment ... right? (bg)
The other less strenuous job would be to change the spring tention on the reverse accumulator piston and possibly change the flow oriface size in the intermediate plate. I personally haven't done this as I am usually working on old trannies that need the problem delt with in the first manner. I know someone who makes a living doing these kind of adjustments. Let me know if you have a technician that is willing to attempt this. It is definitely not a DIY job.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician