Hi,
Sorry for the late reply, I didn’t see this one.
I would remove any other merging / minification plugin as well as to unselect all minification and merging options from other plugins (such as cache plugins that include this option).
This plugin will work with those cache plugins, but it’s more efficient that a lot of them doing merging and minification, since we create static files and many of those rely on PHP in every pageview to generate the minified files.
So it may work, but I recommend only this one to be used for this task.
You can still use a cache plugin, as long as you disable merging and minification there.