I think Jack Sheeks used a COMO 40 in his black Spitfire or Hurricane in the 1970's. Didn't see it mentioned in the inevitable construction article that appeared sometime thereafter.
I had one, and never did try to dial it in for stunt. Today with the approach of flatter pitch props to let engines wind to nearer their power peak, while increasing fuel draw at the same time, in a low-2 mode, might suit the COMO. As I recall, it had a dished form to the head fins that resembled the early X-series STs, and may have been a clone.
Not particularly light, good starting, apparently a bunch of power... Only concern might be parts replacement, unless there's a source of interchangeable ST parts...