I still argue this is a game - not a combat sim in the true sense. It's fun as can be or I and the many others that have stuck since 1999 would not be here.
As it is a game - if you agree with me, then everything you can squeeze out of your ride in a digital dogfight is a tool available until Dale decides otherwise. So, I say go for it if it is working for folks. Skyyr is able to use it effectively.
Anyone remember "death star B-17s" or the original "bomb**** B-17s"? The latter would spawn on the runway, wait for the vulcher to get close, and drop his ordinance taking out any closeby vulchers.
I do not doubt the ability to shutdown and restart an engine is realistic based on what I have read from pilots here, but no way do I buy a simple button or key click is realistic, nor do I believe a WWII pilot in his right mind would shutdown his engine to gain an advantage over an opponent (again - gamey tactic). Oh, and if said pilot had his engine shutdown for whatever reason in a dogfight, I doubt he could keep his eyes on his opponent while investigating the reason of the shutdown and restart the engine