I could say it's not space cadet without centered legends on spherical caps with the additional front printed legends.
And I would largely agree with you. The most disappointing thing about 7bit's Round 6 Space Cadet keycaps is the lack of pad-printed front legends. But I have to believe their absence was a concession to cost. Nevertheless, they are the best "Space Cadet" keycaps anyone has tried to make, superior even to Symbiosis which wasn't sculptured.
What I find puzzling is the apparent love for this design from people who don't like spherical (SA) keycaps (which are the closest to the original Space Cadet keycaps you'll find in production today). This says to me that you have two types of interested buyers here: those who love the original Space Cadet keyboard in its entirety and want something as close as possible to it using contemporary components, and those who just like keycaps with unusual legends. The Space Cadet is very special to me, and I feel a little saddened that its legacy is being plundered just to pander to the second crowd, but that's my neurotic cross to bear and nobody else's. I still support this GB because Oblotzky's heart is in the right place, even if it does aim to please buyers who don't really have an appreciation for the OG keyboard that inspires it.