I don't play with this activated anymore because to me it's a bit too disruptive to have so many tarot slots being taken up by cards aimed at a few specific jokers but as I said you got some really nice ideas going and the mechanic of cosmic tokens are super slick implemented both gameplay and visually so this is all said with love and not critique! 😉
If the cosmics where ever separated as their own additions/mod I'd love to add them and keep as part of the few mods I have. This is a bigger change so I understand if it's not on the table at all, but I'd also think simply having the cosmic jokers in the pool (it's one for every card rank right? Also super cool design from you) and no extra tarots at all, would be better in my mind.
For example the retrigger cosmic with +0.5% retrigger still gets +2% for every 4 of a kind played with that rank, so at least the cosmics I came across all seemed like fun and powerful scaling as is even without the boosts from tarots, and it also forces the player to actually score the cards related to the jokers which is a fun way to shape/incentivize the run for bigger benefits.
Didn't get the "150 total tokens negative spawn" thing so I don't know exactly what that joker is, but maybe instead of a tarot needed to trigger the effect/spawn, all the rare cosmic jokers could have the inherent effect of "if totalt tokens are more than 50,60,70 (or whatever could be the best balance) when selecting blind, spawn the negative card". Or maybe even all the cosmics could have something like that which makes you want to try to stack them immediately if possible, even if that perticular effect doesn't do much for your current run. Keep up the good work!