So I ran Vana recently on advanced and got 0 radiant fire crystals. Then yesterday I did a T3 run and found a little over a dozen in the final few depths. What I concluded was, because the Arcade was once dead when missions came out and made FSC readily accessible, the devs adjusted the drop rates to have Radiants drop more frequently in the Arcade so people would be encouraged to explore the Clockworks.
My only problem with this is that an Elite T3 solo run took me about an hour and a half, which for me is 30 minutes too much.
And I wasted crowns in the slime casino.
And I used 2 sparks on a gremlin arena.
But I found some sparks on the following depths, so that was pretty good.
Also energy prices are CRAZY. 10k cr? I remember when they were 6k, and I thought that was expensive. Imagine trying to craft 2* gear farming the first handful of depths. That's what, 600cr/run? This is some hard-hitting capitalism going on here. We need the GMs to take the rich players' crowns and gear and redistribute them to the masses! Then the SK economy and society would be perfect! We also need ban squads to eliminate players who resist! YES! FOR A PERFECT SPIRAL ORDER!
The amount of Radiants that arises in any given level or mission is random, but distributed near a mean. You have to make many more observations, to get good estimates of the mean and dispersion. So please continue to gather data.