It's been a long slog bringing the system to the RPi line of systems. In the original LMCE release for the RPi I had spent 2 months hacking u-boot to provide a really robust 'PXE like' boot process for the RPi in LMCE. It was intense and required understanding and programing u-boot for low-level memory access to pass boot parameters (ATAGS) properly to the linux kernel. When the RPi2 was released the hardware had changed significantly and the broadcom SOC was upgraded to a multi-core cpu and armv7 rather than the older armv6 architecture. Due to the architecture changes in the SOC u-boot failed to work with the new Raspberries. So I revived the old, old concept of disked Media Directors for the RPi2. This worked well as long as the power didn't go out (which meant you would have to re-write the sdcard and let the system re-install all the software packages again.) With the RPi foundation's recent announcement of netboot capability (https://www.raspberrypi.org/blog/pi-3-booting-part-ii-ethernet-all-the-awesome/) we have a new way to boot all Raspberry Pi B's (1, 2 and 3).
Head on over to http://wiki.linuxmce.org/index.php/RaspberryPi to read about how to setup a network booting RPi Media Director.
Keep in mind that the RPi foundation (and myself) still consider this to be very experimental.