I saw (Through use of a memory editor) That a lot of garbage is compiled in with code. Built-In procs that one may have never even used such as md5(). I understand there may be things behind the scene that Byond uses in itself in DreamSeeker, but to include any and everything, regardless of if it's used is a waste of time and size.
All of this is included from the following code:
mob/verb/a()
world<<"a"
--Edit
And as someone else on my Messenger list suggested (Not naming him, because he might not want to be named. *shrugs*)
It would be a whole hell of a lot quicker to only compile changed files, and link them all together in the end.
Even crc from the last compile compared to the new files to check which files have been changed.