I like to grind out these evo mats with natural refills only. Amolad is the only map that drops both 2* and 3* at a decent rate, at least better than bnw, but still 1* drop more often than 2* while 3* drop even more often than 1*. At least in my experience. Upgrading cosmics isn't that big a deal considering the rarity of cosmic evo runes. I just can't keep up evolving talismans ... We get such an insane amount of them that it's hard to keep up with maxing them out.