That is interesting re. the Accutron, I did not know the crystal was involved in power transmission - rather confused by that so will have to read up on it. Even if one adopts the strange definition that the quartz crystal, when activated by electricity, is a moving part, the crystal is not involved in the transmission of power / wheel train in Spring Drive (or in "dumb quartz") - only in regulating the timekeeping as you say. Whereas in a normal mechanical watch, the balance is part of both the power transmission and timekeeping regulation. If a WIS was so inclined, they could make the additional distinction that moving parts should belong to the wheel train, and by that definition they could exclude the crystal as a moving part in Spring Drive :).