Actually one does not need lots of water to wash wool with modern commercial wet cleaning processes. This could be the reason your commercial Miele washer uses so little water.
The more water wool is floating about in gives fibres that much more water to absorb, and absorbtion of water can cause wool to shrink/distort. Also wool does not attract nor hold soils,so long and or aggressive washing is not necessary. This is especially true if spots and stains are treated beforehand.
Managed to nab some "wet cleaning" detergent and fabric conditioner. Directions for items marked "dry clean only" call for a 5-8 minute wash cycle, low water, slow dipping at first, then long pauses,dips, then long pauses again (this detergent works independant of mechanical action), drain, short spin. Rinse is one cycle again with low level water and the conditoner for about 5 minutes,drain then extract for a short period on fast spin. My cashmeres and other woolens have never been cleaner and softer using this method, with no shrinking, stretching or fading. Best of all the conditioner and detergent block wool fibers from absorbing water and protect from a short fluff period in the dryer (less than three minutes).
The above method works so well haven't used the "Wool" cycle on my vintage Miele,which by the way fills up to about 3/4 or more than a half drum of water. Only time really use that cycle is for laundering bulky items like down filled pillows.
L.