Since the problem is internal you might try experimenting. I would run the modulator in at least one turn and hasten the shift point by at least a turn on the control pressure cable housing adjustment. This is sort of like seasoning; do it to to taste, if you need more give it more.
Since the real problem is intermittant or just starting, these adjustments may put off going inside for quite some time.
Bosch Master, ASE Master, L1
33 years MB technician