Re: Shouldn't we use partition type 63 (GNU HURD)?
The partition type indicates the format of the filesystem data in that
partition. The 0x83 type is for ext filesystems or other formats
that are compatibly identifiable by their magic numbers as those are.
It doesn't matter what variant of ext2 is there, or what system the
filesystem's contents are intended to be used with. That's not
something that a partition type has ever told you.
The 0x63 type has never been used, was never requested or suggested by
Hurd folks, and has no useful purpose I am aware of.