The only requirement is that the packages should be buildable with things that are already in the Cygwin distribution. Since, AFAIK, scons isn't yet, you might want to ITP scons before you ITP lyx.
This is not a problem since scons is python-based so no additional build process is necessary. Lyx will be bundled with scons-base so one can build lyx with 'scons' command at the top of the source tree. Bo
