When they say "low speed kit" I always assumed they meant the 1Ghz gonzalo setup that was unearthed some time ago. I don't think the difference between 1.8 and 2.0 is meaningful enough to call one slow vs the other. Or it was simply still a zen/vega setup. Would those silver PC towers have APUs in them or still desktop components?
I could be wrong on this but I believe Gonzalo and Prospero are the codenames for the entire SoC and Ariel and Oberon for the iGPU itself: ie (Gonzalo with iGPU Ariel and Prospero with iGPU Oberon)
So maybe Ariel was initially 1.0GHZ before going to 1.8Ghz? I dunno hard to keep track of everything.