I've just bought a new plastic chassis and it looks the same as the one that pictured. It hasn't been beefed up or modified by TD.
To help strengthen where the screw head sits I've put the orange servo washers under each screw head, they fit nice and snug in the recess with no lateral play which should help take some of the strain out of the chassis under hard landings.
This is all theory but it should work because the screw isn't trying to twist and compress the chassis material round the screw hole.
I'll let everyone know how it pans out.
