To be truthful, the weak link in the X-2 is the column to base support.

To solve this, a backer plate that bolts the back of the column down to the back of the base plate is really all that is needed.

With just the column to base stiffer, this will cover you with the stock motor and an motor controller up grade to get the motor to put out full power.

Now if you are looking at upgrading the motor into the 2HP range, then forget the upgrade kit since it still will be the weak link (flex between the column to base support. plus you get into the other parts of the machine not being able to hold it own with that much power down to work piece to resolve the chatter city cuts).

B Rad, just looked at your drawing, and it's missing the most important part, being the bottom of back plate to base tie in.

If you look at DJ's mod, you can see that the stock column has only the two front brace bolts, leaving the back of the column supported from just the front points cantilevering to the back. His small brass deals with this issue, being that the support bracket is adding bolting point for column at the back to stiffen the base to column support system. This alone goes a long way to resolve chatter, with some of the other more beef up mod's to stiffen up the entire column as well.