cranesan
I had a similar issue, also in the late 1990s, so I understand the stress around wasting those $20 blanks. Found out a few years later that the drives were defective, and would often (but not always!) have buffer errors when burning discs close to capacity. (something that you'd often WANT to do, to maximize the value you're getting from those $20 blanks!)
There was a class action lawsuit, and I eventually got a replacement drive (no relief for those wasted expensive, blanks). But the vindication that it was defective hardware, and nothing I did wrong helps. The manufacturer of the drive was Philips/Magnavox, but there were some other brands that were all linked back to this same defect that the class action lawsuit covered.
I'd say that it's HashKnownHosts that is impractical, not the attack. One of the reasons someone would publish a tool like this is to raise awareness of the brittle security HashKnownHosts offers vs. modern GPUs.
Please do, I am hungry for details here. The one chart they put in has no scale on it's axis, and as another comment pointed out, they didn't give any details about what recommendations were followed to achieve the improvements.