When did wheel hardness choices change from 92/95/97? It seems so long ago.
When wheels started getting really small. Late 91-early 92ish.
A small 40mm wheel in 95a won't go really fast. They needed to be hard to maintain at least some speed.
Anything under 52mm that's softer than 98a will be pretty slow. Cores help keep the 54mm area soft cruiser wheels rolling though.
The trick to making soft wheels faster is cores.
Why Welcome went with a 104a cored wheel is beyond me. (there's technically no such thing, a Bones SPF is 84b, that'd basically be 104a, but there's no above 100 reading on the A scale, so you use the B scale and estimate 20 points higher to sorta use it on the A scale - mouthful!).
Alot of cores are around that hard anyways at say 84 -86b, so I don't see how adding an actual separate core would help a bearing seat better. Maybe a patent w/ another company that uses the same urethane recipe prevented them from just going with a straight poured in standard mold 1 piece wheel?
Weird, but hey, interesting looking wheels regardless. I bet they are fast as fuck on concrete, but slippery as all hell on masonite.