Repack the archive to include <whatever_you_want> after the "make zip" step, and before the "make apk" step, finish the build with "make apk", done.
This will only change the font, though. The default theme itself only exists for a specific set of resolutions, and in that case, an adequate font is always included in the build. You must be building for an unsupported resolution.
This is a somewhat odd way to achieve this, though. One can achieve an entirely similar effect by simply modifying the config file to point to a font that isn't tiny, extracted to emulated or external storage as intended.
[Saint]