How rough can your evaluation be? You could always just run printer manages colour with Velvet Fine Art media type, if your main concerns are how the surface looks under ink, what kind of Dmax & saturation you can get under ink load, etc. You could print via the 9890 profiles or something else, but they won't be colour-accurate... so at that point all you can really do is check for coarser grained ink load and paper surface effects anyway.
For what it's worth, I've printed on a bunch of the Awagami papers and have no particular issue with any of them I've used. That includes their Kozo thick & thin, their Unryu, and a couple of others. I never tried the Epson Kozo so I have no reference point there. I have used Asuka's inkjet washi rolls, and also printed on various uncoated kozo papers. So far I like all of the varieties I've tried; but for different reasons, as they have really differing response to ink load. The Awagami papers take maximum ink the best that I've personally seen.
I hear you on the presumption of obsolescence. We still run some 9880's, albeit converted for Piezography carbon printing. They are warhorses that just keep charging along, easily our all-time best bang-for-buck printing platform.