If you’re using it more from road surely a racier CX bike like the TCX would be a better option that a tootlier Pinnacle with more relaxed riding position?
Surely the other way around? the Pinnacle is a road bike with concessions for pootling (slightly more relaxed, biger tyres and disk brakes). A CX bike would probably be much stiffer, but even more relaxed to allow it to handle off road?
Fwiw the ridley bb drop is 1cm less than the caadx. I am having this issue a bit as trying to decide on a cx bike for similar purposes but do have the short legs, long torso issue.
The BB height is a European Vs USA thing (Ridley Vs Cannondale in this case). European bikes traditionally have high BB’s to allow riding over stuff like steps and sinking into the mud a lot. CX in the USA is often a lot dryer, more like a crit race on gravel and grass, so the bikes developed around that and handling and speed came first, clearance second.
Left field suggestion, Gnesis Fugio? Frames are £500 from some places, and I’ve seen them down to £299 sometimes, might squeeze a 105 groupset and some half decent wheels into the budget, then raid your parts bin for finishing kit?