The procedure that you mentioned is the one that I also use to compensate for "pulling". It works quite well.
I think I am about the only one here that uses vertical X axis rails for my machines that uses cncrouterparts.com bearing carriages. It puts all of the gantry weight on the two bearings in the top carriages that roll on the edge of the rail. The lower carriages don't support any weight, just keep the gantry support square and prevent lifting when plunging the cutter into material being cut. The horizontal rail method that Ahren recommends and FLA uses can support more weight because four bearings in each carriage carry the load.
I haven't had any ABEC7 bearings go bad so far, just wanted to point out this difference.
If you are going to cut steel, then I would recommend using thick wall box tubing for the frame instead of channel as I am doing. It is generally straighter than channel, and 3/16" or 1/4" thick wall tubing will be a lot stiffer. Bevel the edges that are to be welded so that weld penetration is better. That too is a normal welding procedure, as I'm sure you know.
Be sure to post your build here, of course.