Thank you very much Stilez for this amazing guide. It was pretty much trouble free to crossflash. Just a couple of small comments:
1. FreeDOS already creates some of the files and when you overwrite them from the zip file you may get some errors like command not found or something. This could be a bit clearer
2. Booting from a disk within the HBA requires to flash the boot roms. I read the guide multiple times and I didn't find it quite so apparent. So after crossflashing the HBA the disks were not visible in the BIOS when I hadn't flashed the roms. I think it could be stated in a more explicit/clear way.
Great tool. Definitely it gives quite some level of confidence.
Just be ready, it might take quite some time before it is completed.
Just as a reference: 10x12TB set of disks on Xeon system was up and running for ~7 days before was completed.
But then there is a good understanding about the setup.