If you stick to basic dosages you can get everything to hold at 2% 20%. When you get into High mg gear thats when you gotta add EO but still stick with the 2% 20% ratio when using EO.
Stick to common ratings and ba/bb usually work. Thing like tne and fancy boldonone variants require special solvents but most all other shit should hold at 2/20 ba/bb unless u push the mg/ml