I think this is another one of those "homebrew" type projects, along the lines of the TerribleFire, etc. The designers are starting with an '000 and hopefully moving up from there as they learn.
Still, where the heck do you find 50MHz 000s?
I've seen 66MHz CPU32 derivatives, but nothing this overclockable with an 000 or 010 designation.
And yeah, working with '020 and '030 cpus is SO much more complicated, but there are some operations that are up to 6 times faster.