I think next league I might try to get a couple rarity affix gear pieces and see if the passive income gets better. I've never really liked stacking quantity because of the damage/speed/tankiness tradeoff, but you can get rarity for very low opportunity cost.

Well you would expect a league like abyss to produce more exalts on average than bestiary. Random is random, but higher mob density etc (on top of tons of unknowns from an outside perspective such as comparable playstyle, clearspeed, sextant use, etc) should validate that result (more exalts last league than this league, all else equal) if not the exact numbers.

I have found this to be true even in beastiary. I started the league with a spectre necro to 91. no raw exalts to 91. rerolled a mf ripper. 2 on the way to 91. again in no way scientific data but I dare say if it 'feels' like rarity works on poe currency purchase for many people it probably does.

I'm actually in the middle of my own testing to follow-up on slipperyjim's findings, and I'm not actually seeing this trend. The Frequency distribution of poe exalted orb dropping has a couple of interesting spikes that could be something solid (or might disappear) once more runs are done, but I'm not seeing item rarity "shift currency up a tier" as I'd initially proposed to explain slipperyjim's results.

You would get pretty good data from only a handful of runs given that wisdom scrolls are so common. Just comparing the number of portal/wisdom from 10-20 runs should give you pretty high certainty if rarity works that way.

What you would expect to see is that IIQ/IIR gives about the same number of portal scrolls but IIR gets almost identical wisdom scrolls as baseline while IIQ gets way more wisdom scrolls.