All that the minimum size error is saying is that one of the 9-slice regions for the frame is smaller than 3 pixels in a direction that it may be tiled. This can translate to a performance hit when displaying these frames, especially as the frame grows larger. This happened for frames that were defined with 1-pixel regions, of which I found many. In those cases, I just tiled the frames myself to make the regions larger, and updated the frame definition.
I'm guessing that CoreRPG already has replacements for most of those frames that are throwing issues anyway, and probably don't need to be redefined separately in the ruleset anyway.
JPG

