Please open an issue (if there isn't one already) on our bug tracker for this. By opening an issue, it will allow our developers to look into it and keep track of progress. You can use the "Report a packaging problem" template. Thanks.
Keep in mind that X11 is going to eventually be deprecated for XFCE. Long term, Compiz is going to be removed since it only supports X11. We can make Compiz not require MATE, for now.