As some have already noticed Protogon is not working. I am quite confident it's because it is broken in the current build. Earlier versions worked with protogon, like 6.2.7955, but not in 6.2.8102. So I tried to replace a few files and as expected it is possible to format with protogon under 6.2.8102. For that you need 4 files;
format.com ifsutil.dll untfs.dll uprotogon.dll
Put those in a separate folder and formatting with protogon will work like this;
As you see, the last line says format failed, but that is wrong. It only says so because the protogon driver in the build is broken and thus cannot understand/verify the filesystem on the new volume. I did this and verified the volume to be correctly formatted by reattaching the disk to a build that has protogon working. Using older version of protogon.sys was also not possible as the system then bsod'ed (or more exactly g(reen)sod'ed complaining about ntfs something error).
Moreover, the minimum volume size supported for protogon is exactly 512 Mb. Bootcode is also not supported yet, at least bootsect.exe complained. As expected it is thus not possible to boot directly from a protogon formatted volume. And the size of the systemfiles seems to be less than on NTFS, and giving more of the available space on the volume.
Anyways, it's interesting to have a new filesystem to be dealing with. Don't know what else it is capable of yet.
Oh and btw, the OS itself, was really a big pain. After a couple of hours back and forth in Virtualbox, I still don't know where the shutdown button is. And the programs menu, was nowhere...