4 bytes to spare isn't surprising. When you're crunching things down, you stop once it fits. I once worked on a project that used 4x of its memory space when the project was half done. When I was done, I had 13 free bits of space. Yes, bits; I was doing a lot of bit picking to get it to work.

What was surprising is the lengths they went to to make things fit. A solver? Wow. My problem was relatively straight forward in comparison: just bit packing and silly amounts of code reuse: Hey, these two completely unrelated routines have the same 7 byte sequence; can I make it common?

Fun times, I miss projects like that.