I know how to design a paragraph style that keeps the last lines together so that individual lines in a column followed by a subtitle are avoided. Unfortunately, this makes that some columns end earlier than others. They simply aren’t filled out completely.
The column isn’t filled completely cause InDesign insists on keeping those two lines in the next column. I think this is because of “keeping lines togethe” options in the paragraph style. In general, I would like my columns to be filled to the max too.