LMS is needed to send sound to the Squeezeboxes and sync them. MC cannot do this on its own.
I have now set LMS to an empty folder, i.e. no tracks in the LMS database, removed all unnecessary plugins and use only MC to send tracks to the Squeezeboxes via Whitebear. It works very well for me, better than it worked with only LMS since I have a collection that is obviously too large to be handled well by LMS with Erland's plugins.
I use a test version of Whitebear with some important enhancements. I expect Andrew will release a new version of Whitebear soon.