Hoperfully he will do engineer's job at Bristol.
Let's say he 1st does some cleaning around Hercules' supercharger. It is already of decent size (13.25 in impeller), so now (mid 1940)it should be making +3.25 psig at ~17 thousand feet, rather than at 14000 ft. Improved Mk. VI should go at +6 psig at ~17 kft, in 1941. The resulting improvement of engine power at altitude makes Beaufighter a better performer, Stirling also fares better.
Hooker's next stuff is the 2-stage compressor. One of trial installations was at the Tornado, and it outperforms the Typhoon and Vulture Tornado above 20000 ft. What is also important, it outperforms Bf 109, Fw 190 and Spitfire IX above 20000 ft, by a small margin. The Spit IX climbs as good, however.