features is a list of arrays, one per feature, and there can be any number of them. Build a Figure with at most three columns and exactly enough rows to hold them all, plotting one feature per Axes in order.

A grid that does not divide evenly leaves spare Axes at the end. Remove them from the Figure rather than leaving them blank, so the Figure holds exactly as many Axes as there are features.

Return the Figure. Hiding a spare Axes is not the same as removing it -- a hidden one is still part of the Figure.