If the controller can operate from standard GCode programs, then there should be only one problem. The interface between the PC/Linux machine and the controller have to match. The current release candidate of MillMage supports a USB link, but I do not know if Ethernet or WIFI is supported.
To find out, download the latest release candidate and test it. Please come back and let us know what you discover.
LinuxCNC is a realtime control systems that interprets g-code and converts it to step/direction signals using the FPGAs in the MESA card to handle the the step timing and IO.
MillMage is a CAM software with an integrated g-code sender that works with GRBL, Smoothie or other serial based controller firmwares.
What you can do is generate G-code for LinuxCNC in MillMage. We will never replace LinuxCNC, Mach4, UCCNC, or other real time PC based control systems.