fortran is fortran!
in diving into the box, the programming seems to keep building over the years, rather than start over and revise the coding.
I have found several instances, where calculations have been added in several places, and are in conflict with each other, and rather than fix the conflicts, a workaround is added.
Look at 10.8, fully vetted and approved, yet a disaster installed....10.8a fixed somethings, but added other conflicts...