And it only took 4 years of campaigning to get it!
Nine years is what I count.
And lots of the aircraft and vehicles forum posting as well.
That said, who knows how soon HTC decided that was something they wanted to do and simply didn't get around to it until the Mossie was redone. The Mossie VI with ejector stacks is honestly one of the things that keeps me attached to AH. The easy data for the Mossie is with flame dampers, or even with Merlin 21s, and it is how most sims end up modeling it. In WarBirds, for example, the Mossie VI had a top speed on the deck of 320mph, the same as ours does on MIL.