Define independent Initiative Matrix views

Currently, you can rename the axes in the Initiative Matrix once, and after that your 2 values per axis are intended to be aligned.  So Effort & whatever you rename Effort will always have the same value.  It would be nice if you could instead create a variety of matrices, and have the axis values be independent of each other.  While I could conceivably create custom fields and use a custom bubble chart to recreate the views I want, my team prefers the drag-and-drop interface to update the values - much more interactive than a static bubble chart that requires manual value updates behind the scenes.