Alex Ranous:
What I do is bring in my finished image from PixInsight into Affinity Photo. In Affinity, you load the Bay Photo ICC profile into their soft proofing tool. In the soft proofing tool you apply a layer using that profile, and the image is adjusted so that it'll look like what the printed image will be from their printers. You then adjust your proofed image to get it looking like you want it. I usually end up having to significantly brighten the image and maybe bump up the saturation. When you get is looking like you want, you save this adjusted image which you can then upload to Bay Photo. You can also use Photoshop for this as well. You can find youtube videos that demonstrate how to use the soft proofing feature.
Thanks Alex!