What 4drX says: make sure to use these settings, otherwise you will need to ship the redistributables for other people to install on their machine (you could do that as part of your installer, but it’s much easier to just use the static runtime, even if it makes your plugin a bit bigger and bug fixes into the MS libs won’t make it into your plugin unless you rebuild). See also: Do plugins need Visual Studio redistributable?
And related to Eigen: it’s a template library IIRC, so you don’t need to install anything on another machine for it to run (it’s all compiled into your code). More info: http://eigen.tuxfamily.org/index.php?title=Main_Page#Requirements