Here's more thoughts, regarding HOW TO shut off a (rotary signal) switch, when the energy for doing that is supplied by...(You guessed it); supplied by, or sourced, by the double-pole switch itself.
Imagine the moving toggle; when the toggle, in standard electric switch leaves the 'pole' contact, that energy is stopped, and same thing occurs with mechanical commutator switches; that is, the source that causes switch movement, in the first place, is no longer there. A small flywheel, perhaps, or some kind of spring, could maintain power, as it winds down; pushing the switch to complete arc of travel. By using split paths, the arrangement can maintain power, in a portion, (actually literally in the next station), and the 'turning off', or de-selection, can occur, crossways, from right side, over to go transparent mode on left side portion. The right side, in current station, has been put into transparent mode, already, and with the actual right side 'active' state actually being in the following station (confusing!).
That is a situation where the 'active' status is 'smeared' a little, across a couple of stations simultaneously.
A FLYWHEEL ?? Man, this sh~π's getting out of hand (lol)...What's next: ...I can't even think of anything, that this design process can't top...
How about: Requirement for a FLAGMAN and two flares, for warning folks: "Warning, Mechanical Switch."
...
At any rate, like I said, these are interesting questions, I want to know, and PLUS, besides, there could be other projects that come up, for experimenting with Mechanical Logic options.