Since the motor is responsible for parking the wipers, I would say that the motor was damaged when it jammed and your choices are to replace the motor or live with the wipers parking where ever they want. Adjusting the blades is only going to lead to problems, as you pointed out. I have 2 wiper motors and only one of them is bad, so I can control where it stops and the good motor still parks itself properly. When the second motor goes bad then I will invest in 2 new wiper motors.
Berniece & Russell with LilBit a Netherland Dwarf rabbit
1987 Southwind, 1995 Ford F150 Supercab 4X4 toad
Life in the fast lane? No thanks! We will stop and smell the flowers at every chance.