This is my first attempt at a mosaic.  This is the Boogeyman (on the left) and Casper the Friendly Ghost (on the right) Nebulae, along with part of Barnard’s Loop dividing them.  The mosaic was imaged in 2 panels, Casper when I first got my Edge 9.25 last October/November and then the Boogeyman later in February and March.

Processed entirely in PixInsight: Both panels were acquired, pre-processed and some post processing done separately.  While still separate panels, they were pre-processed and stacked using WBPP.  The output files each had BlurX (stellar correct only), Gradient Correction, SPCC, BlurX (stellar correct, reduce halo and non-stellar adjust, auto-PSF) and then the DNALinearFit script was run to ensure even brightness of the still linear data (@Pepito Calderon pointed me to that script).  I tried creating the mosaic with both Gradient Merge Mosaic and MosaicByCoordinates, but both had visible seams where there was a slight variation in brightness in the overlapping Barnard’s Loop and seemed to introduce a color cast and change in brightness, differently for each entire panel.  @Jonathan Stockdale pointed me toward another script, PhotometricMosaic.  This worked beautifully and made an invisible seam.  The data also looked like the original after the merge with no color cast or change in brightness.

Once merged into a single panel mosaic, I did a partial GSH stretch until I got the stars close to where I wanted them, removed the stars with StarX, stretched the starless image further using GHS, and tweaked using the SelectiveColorCorrection script (if you haven’t tried it yet – do!  It’s very powerful with awesome built-in mask features), as well as ColorSaturation.  A very slight BlurX non-stellar adjustment was performed with a fixed PSF for a slight bit of sharpening.  I stretched the stars a little bit more with a histogram transform, increased their saturation a little with ColorSaturation, and added the stars back in using the ScreenStars script (my go-to that I always use for that purpose).  The re-combined image with stars was then slightly adjusted using histogram equalization and the EnhanceDarkNebula script.
Like everyone else, I may go back and try processing again to see if I can bring out any more dust.  Otherwise, I’m pretty happy with it.