Hi Neptune,
Miele washers are the "Mercedes class" amongst laundry washers and - of course, the most expensive ones to find in Germany.
You won't find a label on the motor I guess since they are manufactured in Italy, custom made.
Even if the timer uses a synchronous motor you can set accurate timing by using the factor 1.2 for programming the washing time, e.g. desired time 1 hour you might select 72 minutes on the scale for that time.
I'm pretty sure timing won't be an issue for the reason I already posted.
Overheat would probably occur using a motor designed for a higher mains frequency. (In your case you are changing from low to high frequency.)
Aircraft electric DC power is gained from 110V/400Hz and the transformers are comparatively small (small iron packet) to save weight.
The motor won't run harder, but slightly faster (20%) than normal. RPM depends on the number of poles and mains frequency.
You might probably run into problems when the machine spins the laundry attaining an rpm region with the drum's radial speed going supersonic.
So be prepared for a sonic boom.
Regards
Boncuk