Note also that every single-engine fighter can use the E key to instantly turn power on and off. All twin-engine fighters (P-38s, Bf 110s and Mosquito) all must go through the normal start sequence if they shut down engines.
Since we have the new P-51s, P-47s, P-38s, 190s and Ki-84 and this gamey option still exists for all but the P-38s...I must assume that it will still be present with the new Spitfires and 109s.
Since this is somewhat confusing, perhaps someone can provide an explanation why:
1) It exists in the first place.
2) Why multi-engine fighters are different.
In my opinion, based upon well over 2,000 hours as Flight Engineer and Crew Chief on radial powered military aircraft (R-2800 and R-1830) is that no aircraft should be able to cut power and instantly restart without performing normal restart (as on the ground, or an air start procedure).
My regards,
Widewing