I get what you're saying BR that it differs when scaled..
I'm probably connecting dots that aren't there but it does seem to fit a pattern. 90,180,270,360. So far the only theory is that that is just how it is because that's the way it's always been. There's no rhyme or reason to having 27.1 carved into stone- it could've just as easily ended up at 28 degrees had the person that set up the track had eaten their Wheaties that morning contrasted too had they been functioning with low blood sugar while setting up the track it might've been 26 degrees.