How to balance last page of two-column layout?

I'm not sure about Koma-Script in particular, but I've had reasonably good luck using the flushend package with a variety of conference-provided document classes. The use is pretty simple:

\usepackage{flushend}

and that's all it takes. There can occasionally be issues with pdf links being broken across columns.

\usepackage{balance} in the beginning of the latex document, and then add \balance somewhere in the left column text of the last page.

You can also use \usepackage{multicol} and use the \begin{multicols}{x} environment where x is the amount of columns. They will automatically align themselves according to what you want.