I've found this thread from that RS discussion.
The RS kit is overpriced IMO: the case is mediocre, the default plate is so-so too and with keycaps and switches not included this effectively leaves you with 130 USD PCB. I skipped and will order UK78 PCB at least. I can cut plate for my layout (not universal) from any material I want, I can cut case too, actually (but I really love the design of Fjell, so maybe...), I've got switches and keycaps enough to build a close-to-endgame board for home usage. So I'll stick with this one.