I am hoping that the folding section will work. I wanted it to be tool less so I am hoping the current design will work, although I am slightly concerned about the way the mechanism moves. Failing that I have a second idea, but it will mean more weight.
good suggestion about the horizontal plate for the arms, also will add somewhere to attach the wires from the motor too!
Currently not thinking about a cage for the electronics, although am planning on making some raised platforms on the top plate to mount them too. Although they will be optional and will just provide extra mount points for all the electronics for an FPV capable quad.
I am starting to struggle mounting all the stuff on my F450 frame. Next few months will see me buying the FPV kit (probably from you ) and it will be interesting fitting all that on!