Extremely pleased to share this one!

This one exceeded my expectations in both the amount of time and effort required to complete every step from start to finish, and the final image that resulted.

I spent 21 nights worth of imaging to acquire all of the subframes. At some point lost track of how many times I had to set up/tear down the scope in between stretches of clear nights. Originally I was only going to do a 3 panel mosaic spanning across the heart and the soul, but towards the end I tossed in a 4th panel to fill out the image for a roughly 21:9 aspect ratio and was happy to capture some of the faint Ha signal off to the right side.

I'd guess the processing time required to crunch the raw 1292~ subframes in WBPP was probably in the range of 20-25hrs on a Ryzen 9 5900x based system. Each WBPP run for one filter/one panel was somewhere between 50min to 1hr15min~, so 4 filters*4 panels, that's about 16hrs without including any redo runs while fiddling with settings, or the final WBPP run including drizzle integration.

My process for handing the background gradients between panels was to first run a light pass of NoiseXterminator before doing anything else, and then DBE(division with normalization), followed by 2 passes of ABE(division with normalization) with a function degree of 2 and then 1. I used GHS for stretching before manually adjusting the backgrounds and nebulosity to match across all 4 frames of each filter using Curves, and then ran Image Solver with high quality distortion correction on every filter/panel before using Mosaic By Coordinates to produce the final mosaic aligned frames for each filter/panel. With those final mosaic aligned frames, I used GradientMergeMosaic with a shrink radius of 3 and Feather radius of 15 to produce the final 4 merged mosaic frames.

At this point I was able to use StarXterminator batch processing over night to separate the stars so I could process the nebulosity alone. I don't have an RTX based graphics card so this took nearly the entire night to complete with the 5900x. Once I combined the filters to produce a color image, I realized I had forgotten to star align all 4 mosaic masters before cropping and running StarXterminator , so of course nothing matched up and I had to go back and star align/crop/redo star removal to have matched pairs of Ha, R, G, B, Stars+Starless. 

With the bugs worked out, the final image came in at 26010x11905, or just under 310 megapixels, and 7.3gb in a 64bit xisf. I used the Ha data as a Luminance layer and then R+(Ha-R), G and B for the full color image. After that I tried Bill Blanshan's HHO Narrowband Normalization script on a whim to see what it would do with my HaRGB data. I know the raw data was shot without an OIII filter, but I had to stick with what I saw from his normalization script because the blue and gold wowed me so much more than the overwhelmingly pinkish-red HaRGB image that I started with. I'll have to pick up an OIII filter at some point and add to this again at a later time.

Towards the end of processing, PixInsight decided to exit to desktop with no warning whatsoever(I think I ran out of ram with several 4gb+ files open) and I unfortunately(stupidly) didn't save anything between redoing my StarXterminator process and the stacked color image processing so I got to do that all over again as well, but this time with the addition of BlurXterminator which drastically improved my star shapes across the mosaic merge borders where the image corners overlapped. I used star sharpening with roughly the default settings, and non-stellar sharpening very lightly which I found worked well in place of using DarkStructureEnhance to bring out the fine dark structural detail without crushing the darks down in the process. I feel like this difference was most noticeable in the region to the right of the heart.

With all that said, I hope everyone enjoys this one as much as I do. This one has been my favorite project to shoot yet despite the overwhelming amount of time required to finish it, but I will still plan on "going big" on integration time with all future projects as well.