Because there are switches internally to the lib. Certain things are enabled/disabled depending on the project you choose (SCD vs hucard).
I advise you to put as much as you can in library.asm. Use lib bank #1. Also, try to
move/reconfigure some other non important stuff in lib bank #1 into lib bank #2. This'll free up more space in the lib bank for you. But you'll have to look at/figure out the far mapping system they use for lib bank #2 calls. It's not too difficult though.
You really have to know the system and layout of Magic kit and HuC, when you start adding asm routines like that. Because of all the banks and mapping, it's not as simple as just including some #asm code.
Nodt went through and remove a lot of stuff he didn't need. The problem is though, some of the stuff that might be extra space in a hucard project - won't be in a CD project (because the system card already has these functions). So removing some, might not even effect a CD project.
I have make a mix with all your h-sync routine
Hopefully not the old one. The old is not just slow, but bloated/large as well. And if you use my ACD routines, they'll also increase the size of the CD project.
If you're having troubles figuring some of this stuff out, I can help. But I'll need access to
some of the source.
Also, the reason why I recommend lib bank #1, is that it's always mapped in place. When you do includes and such into HuC, you can't really rely on where it'll be. Something might change and it might be mapped into far memory, and possibly crash on calling it (depends on how you're doing this. I can only speculate your setup/code/etc).