326x326mm bed support for J-Bot Core-XY?

I can't support a 326x326mm bed with the existing models because I don't have enough space for the holes in the corners.
You would need both these mirrored things for the corner holes.
I use the JonnayLin support for the 3rd hole, but for a 4-hole bed you would need 2 pairs of these ones.
The design is meant for use with springs with a 10mm diameter and spacers like on http://www.thingiverse.com/make:323057
I did some countersinking because I like washers to spread the burden.

The space-problem would not exist with the D-bot, I suppose, although... this 6mm plate alone weighs some 1.7kg.

I am still busy building the frame, so I'm not sure, but I don't see any other problems rising from the size of this plate.

Edit: to decrease the chance of bottoming out of hammerhead nuts I made some room around the 5mm holes at the profile side => V2. Thanks to KDan.