Although the CAD drawings are shown in a static position Adrian, on the computer the axle can move through its full arc and thus I think your concerns have been allowed for.
Maybe I did not explain very well, if one wheel goes fully down and the other side fully up at the same, then the axle will be at an angle to the swinging arms causing the twist/torsion on them. I know this is unlikely to happen to this extreme unless you go trialing but it will be there to an extent as one side moves up an down as opposed to the other. I hope that makes sense. I am not criticising just just trying to make a possible observation, that might be useful.
