This is a great idea - I love the maximise hills option :) It reminds me of one of our clubs TT routes which featured 1100M (3600ft) of climbing in 28miles, this would be great for generating some similar routes I reckon.
I know that Castle Coombe has regular bicycle races - both criteriums and time trials.
Pretty sure many of the circuits do, as its a good way to use the track and get some cash in, as they are often regulated in the number of motor races due to noise issues.
Yes - very true. I race timetrials and keeping a stable aero position requires effort and practice but it's worth it as the gains from aero improvements can be huge.
https://cyclinguphill.com/bristol-south-mega-hilly/