Also: I'd revert the change where you only unlock enemies of the element type you've researched. As it is it is almost better to not research some of the element types because you can just put more points into white defense.
Recommendation: change it so that you can't upgrade a blueprint for items you haven't researched yet. As it is you just max the best upgrades first and are done.
REALLY needs the ability to auto construct needed components that a crafter can make. IE making an earthquake scroll but you have no magic scrolls or earth scrolls? You click to build earthquake and your builder automatically builds 2 magic scrolls --> 2 earth scrolls --> earthquake scroll. Individually queuing up for components is an enormous hassle and is making me want to abandon this game.