In Windrush the mandatory solenoid is fitted, as it should be, downstream from the regulator. Willy Occam wouldn't like it, and neither do I. SOP is to keep the manual valve on the tanks
closed at all times. When starting a galley
session I open the manual valve on the "current use" tank. When finishing in the galley
and the last pot on the stove is up to temperature, I close the manual valve and let the gas burn outta the line.
No inconvenience at all. And no worries about failure-prone electrics.