Not exactly a bug report but feels more appropriate here than feature requests.

The BYOND Makefile creates a byondsetup that looks something like:

export BYOND_SYSTEM=/path/to/byond
export PATH=/path/to/byond/bin:$PATH
export LD_LIBRARY_PATH=/path/to/byond/bin:$LD_LIBRARY_PATH
export MANPATH=/path/to/byond/man:$MANPATH

It might be more appropriate to make it create it like this:

export BYOND_SYSTEM=/path/to/byond
export PATH=$BYOND_SYSTEM/bin:$PATH
export LD_LIBRARY_PATH=$BYOND_SYSTEM/bin:$LD_LIBRARY_PATH
export MANPATH=$BYOND_SYSTEM/man:$MANPATH

Since it's already exporting the base BYOND path as a env var.