@TW_Tones, I went looking for the plugin that adds a $hover widget and discovered that I’d linked you to it before—so here’s that thread, in case it resurfaces any other ideas you might be looking for. (I note that you did share a package that switches tabs on hover. 
) Is it possible to trigger an action on mouse over or hover?
IIRC, I’ve wrapped a $hover around a normal $button in the past, so you could probably make an alternate tab button template that preserved the normal tab functionality, too.
Perhaps wrap the $hover/$button in a $list/conditional that only displays your modified tab button if <<currentTab>>'s text field contains your target widget, and falls back to the standard button otherwise?
I do like the concept, BTW, though I’m not sure I have an immediate use for dropzones in the sidebar. Do you have any specific use-cases in mind?