Right. My point is that I wish more people would reach instead for a fixed point lat/lng library. It would almost certainly be easier to reason with for most people. Similar for most people doing financial math should probably use something other than IEEE floats.
And again, IEEE numbers are amazingly well done for what they are. Which is largely the digital version of scientific notation that is using base-2.
It's quite difficult to find fixed-point number systems that include trigonometry, never mind fancier tools like elliptic integrals. The problem is not just one of static number representations, but also geodetic/geometric computations. [ed: I see this is where the other thread is heading already]