And 7x7 and 8x8, in the years following that paper. 
Which is why we can now “solve” 7x7 and 8x8 better than any prior attempts at determining the best play on those board sizes (https://katagobooks.org/).
Updated the other thread with some more unlikely speculation. AI suggests nonsense moves on 1st line - #6 by hexahedron
I guess only anoek or someone with more detailed access will ultimately be able to say.