Thanks to WreckRman2 of rcgroups.com for submitting this modification :

The modification is a receiver (rx) mounting platform to keep the rx as far away from other components such as the ESC which can cause interference. The bottom picture shows an additional piece of clear plastic to keep the wires away from the collective servo.

The mount is made from a spare divider from a big organizer of drawers.....the big ones with 30 or so little drawers to put stuff in. The divider was heated with a heat gun and then bent to shape once it was pliable.

This is just an alternative fixing position to placing the rx between the frames, the receiver may be a little exposed to crash damage up front in this position but it will certainly be plenty far enough away from other components to not introduce glitches. This mount position is probably more suited to veteran flyers who are less likely (!) to crash, beginners would be better off protecting the rx between the frames.