The tempest mk v would be my top pick for the next dcs ww2 module. It really had some innovative features, spring tabbed ailerons, MUCH better wing design, etc. As a (quite shitty) mechanical engineer I have the greatest respect for those who designed the sabre engine, and its my favourite engine of the war for many reasons. The short stroke in comparison to every other ww2 engine, combined with the relativity low capacity per cylinder, spot on reciprocating and rotational balance thanks to basically being 2 flat engines on top of each other, and the lack of inertia from valve springs/valvetrain made it the highest revving aircraft piston engine.
Looking at the frankly quite ridiculous ammount of precision required in making the thing during wartime with the problems of metallurgy inherent to sleve valve engines and severe lack of oil quality in those days, its no suprise had problems at the start.
Something I find cool is that it was the only engine from ww2 (from what I know) to make 100hp/l, at least in prototype form.
Plus, we need an actual late war british fighter to go up against the germans since we dont have that yet ;))