That will, I've been working on a mod that allows you to make the minimap bigger for those of us running higher rez. You can I guess make the minimap smaller the same way. The key thing is that the minimappanel.xml only changes the button and frame around the mini map.
You have to change both to make it work and I'm still working on numbers that look right in both as Fraxis had provided no documentation on what the numbers mean within the file.