I currently use the 4100 and 5200H files as they give a V or Gaia g mag (I work unfiltered) and it allows the colours index of each star to be assessed.
One interesting thing to try is the Astrometry.Net –verify option. Got it going at the weekend (I use FITS bintables to identify star locations via columns of x, y, flux). Improves the number of stars employed in WCS polynomial generation (smaller median errors) and also helps Zp estimation. A useful refinement I think.