Something is wrong there that I do not see. I looked again at your Dec 17 support file and I do not see anything that could be causing this. With all MacOS past 13.3, the SoftRAID driver always is loaded, which would be the main reason a file system cannot be created.
While I do not think the problem is softraidtool, lets try "uninstall SoftRAID" from utilties menu, then launch SoftRAID and install again (You will need to reenter your serial number) Then try again.
Also, assuming that does not work, can we try a clean install new System? It does not affect your boot volume, just a second system.
Run Disk Utility
Click on your startup internal
Click + volume
Name/save your volume
Shut down
Startup in recovery mode (hold the power button)
Select Options
Select "reinstall MacOS"
Point the installer to your new volume and install.
Do NOT migrate data, etc. Use the same Admin name.
install SoftRAID. It will run. You can even activate on both systems.
You can delete this second volume at any time. this will confirm whether there is a problem inside your system, or something else, perhaps a problem in the SoftRAID partition maps (which would require a backup/restore to repair, most likely)

