Make Include/What Do You Want to Draw checkbox-based rather than select one

In figure drawing, animal drawing and faces & expressions there are more than two options to choose from for in the include/what do you want to draw sections. Could it be made to be checkboxes kind of like the ages section instead of pick-one? I'd really like to draw more than one category in these, especially when some of the categories are very small. This would be so helpful!

Let me see what I can do! :)