I've stuck to a somewhat limited set of projections in Guide
so far, mostly because I don't like having to deal with
mathematical singularities in projections. The four currently
supported by Guide all have a single, point singularity, all
conveniently 180 degrees from the center point of the chart.

Getting Guide to use an "all-sky" projection would require
modifying quite a bit of code. But I just checked; doing this
would indeed be troublesome, but might be a two-day or three-day
task... and you're right; it _would_ be nice to have. (Once done,
all-sky charts would be available not only in galactic coordinates,
but in RA/dec, alt/az, and ecliptic coordinates.)

-- Bill