What's with "very partial"?
Does Rakudo/JVM pass 100% of the specification tests for P6? No? Then it's a partial implementation of P6.
Imo, if Parrot had been "designed specifically for", or even sufficiently for, Rakudo, then Rakudo would have reached 6.0.0 as Rakudo/Parrot...
Yeah, the sad reality would be a lot different if Rakudo developers hadn't chased away almost all of the Parrot developers with a multi-year campaign of FUD. (Don't believe me? If you're truly interested in an honest accounting, you could ask them.)