You are so right, I used to work on the process machinery used in the manufacture of semiconductors very tight tolerance type of stuff, and know all to well the issue of "cascading measurements".
This is the type of thing can really throw off the performance of an aircraft if you don't get it right, and it all boils down as to how good your reference is.
I would imagine it is even more critical for precision aerobatic aircraft to get the setup dead on to start with...