ok so im gonna make an attempt right here n now without any testing of it. an extra variable called timer
[AG] = what ever group you're using
[11delay] = an extra bit of code in the variable tree

variable name | variable code
11delay (floor(smooth(clamp01([AG]), 1/11))

code to be placed on the engine
11delay>0?0:[AG]

11delay counts down a timer after [AG] is pressed, when 11delay hits zero it will be true or 1 and thus greater than 0. making 11delay>0 be true as well which then makes the switch from [AG] (which at this point in time is active) to the 0.
you've been possibly been waiting for 3 years. I hope this works for your bomber.

Yeah but I don’t get that much thrust from missiles. My plan is to use these on my current bomber project to give an additional 44,000 lbs of thrust on takeoff. This project weighs over 300K lbs already because I’m going for realistic performance.
@ThePilotDude

I'd suggest using a missile instead, wouldn't require funky trees and it looks cooler