I'm not a Maxima developer, so take my opinion accordingly, but
perhaps the following isn't common working knowledge among all the
active developers:
Indentation and other whitespace makes no different to the compiler --
it exists to making code human readable. Proper and consistent
indentation is tremendously important for catching errors and to allow
the eye to extract code organization immediately.
But small changes in code that affect large indentation regions harm
the readability of version difference reports.
Fortunately, most of the diff-based tools used by source management
systems have various options to suppress whitespace difference, so
developers can get the best of both worlds. For example
cvs diff -bc ...
makes the indenting problem pretty much go away.
By the way, the tremendously useful Emacs compare-windows command has
an option to ignore whitespace differences.