Less of a bug report and more of a feature request: It would be nice to have a "Repeat until X storage more full than Y storage." (Either by raw number or by percent storage full would work for me.)
Motivation: When I add automation for producing a new resource, it sometimes drains my supplies for the whole pipeline until that resource is full. (In a concrete example, when I added metal / metal plate production, it consumed all of my coal, which in turn consumed all of my logs.) I can add a "repeat while [ingredient] storage full", but that just moves the problem somewhere else. Having a way to balance production based on available inputs would be helpful. Then again, maybe this is moving the robot scripting language too close to a full-blown programming language (with variables and comparisons and the like), and I'm not sure how you feel about that design-wise.