Here is a tip for anyone who is finding their FFG binds up after installing the diff cover.
Make sure the screw I show in the picture here is not too long (it is too long in the picture). If it is too long it will foul the diff cover. This is a problem with the alloy chassis and might be for carbon too but I don't know.
If the FFG moves more one way than the other then it is likely not centered properly. Undo the screws holding the FFG at the rear and carefully reposition it and ensure it remains central whilst tightening the screws.
Also check your battery is not too far inboard. It can foul the FFG also.
Make sure all the stops are not pressed tightly or this will restrict movement.
Ensure that where the gearbox goes through the bulkhead is free from dirt and debris and that whatever tape you have used here is still smooth and clean. I am replacing this tape after every meeting so far. To make this easier I am now putting the tape on the gearbox not the bulk head.
Hope this helps!
EDIT: Forgot to mention make sure the diff cover is closed properly once installed on the front gear box. Mine took a little wiggling before they snapped shut properly and it was possible to tighten everything up with the diff cover not closed properly.