I've had some issues with the squareness and staility of the bear frame (the extrusions were not cut at a right angle). Since I couldn't find a set of braces that did a job, I came up with this. 

I have the mainboard and power supply mounted beneath the printbed so there are no clearance issues. With the set up according to the manual you might run into issues.

Also you'll need 4 M4x8 bolts and 4x M4 T-nuts to mount it. Putting it together is a bit finicky, but if you loosen the z-axis extrusions you can slide it in.

Also, I have a cable chain and there is a version with a cutout and mounting holes. Just in case someone wants to go down that route as well.