Great job Paul, a picture does say 1000 words. I posted an article about this process about 6 months ago (with the pictures). IMHO this is one of the most versatile uses possible for LEGO. I first noticed this use about 15 years ago when I saw a (...) (24 years ago, 26-Mar-01, to lugnet.space)
While one cannot pick "the one and only piece I want (in infinite quantity) on a desert island", it is possible to pick the single piece that would *most* cripple advanced construction possibilities if it were missing. This piece, the "switcher" as (...) (24 years ago, 26-Mar-01, to lugnet.space, lugnet.build)