Sourmetal Salts: where do it drop? and any special tecnich or place to farm it fast?
From lvl 70 casters mainly ... anywhere you see a lvl 70 caster, it can drop a cache with it. Purple Lotus Swamp is generally the best for it, but there are other places, like Khesh with lvl 70 casters
The spreadsheet on page 1 is actually quite good. I was using an even older one for a long time. Some bits you can fill in by going to aoc.yg.com