On mapcharts please add customisation to the way labels render.
Minimum:
Ideal:
Of immediate concern is the fact that labels render with a hard-coded border no matter what - even if you specify an image label, a border is still enforced. This defeats the object of being able to set label images.
Images also lose their alpha when specified - or do they? Perhaps the label is filling a white bg colour no matter what - in which csase being able to remove a bg colour as above would fix this.
We were recently excited to try to use map charts for rendering scalable infographic style visuals (as per the good old vending machine tutorial), but the restrictions around labelling are putting a blocker on the whole approach.
I recently came across a very similar problem. I used mapchart to display polygon data, and generated a set of labels to use as X and Y axis tick values. The result looks like the attachment. Acceptable but not perfect.
PS:
A cleaner alternative though is to add a Polygon visualization type, which would also resolve the axis title issue.