MM sells two different bumpsteer kits. We don't source either of them from Baer or anyone else. Several years ago, while developing our own kits, we sold the Baer tapered stud kit.
The tapered stud kit (MMTR-2) is for cars that have stock K-members. It will generally give enough range of adjustment for a car with a stock K-member. The spacers in it are made of 4130 steel so they are strong enough to allow the nut to be correctly torqued without deforming the spacers. This kit requires no modifications to the spindles.
The bolt kit (MMTR-1) is for cars with aftermarket K-members. These cars need a larger range of adjustment than ones with stock K-members. The stud size that fits in the stock spindle isn't large enough in diameter to have enough strength when the tie rod is lowered 1.5" from the steering arm. The bending loads in the stud/bolt will be too high since it is loaded in single shear. The solution is to drill out the steering arm of the spindle for a 5/8" bolt. It has a much higher bending stiffness than the stud used in the MMTR-2 kit. It is possible to drill out the spindle on a drill press if, you have several incremental sizes of bits and the drill press can be turned very slow. It wouldn't hurt to have the hole drilled then reamed out by a machine shop to get a very round and precise hole, but it isn't necessary. I've modified numerous spindles on a drill press without any signs of fretting after the suspension was taken apart later. The spacers in the kit are also made of 4130 steel so they are strong enough to allow the nut to be correctly torqued without deforming the spacers. These are the only bumpsteer kits that I'm aware of with this feature. Drilling out the steering arm of the spindle is not a strength issue. I'll post a photo later of an AI car that was in a front end collision with the MMTR-1 bumpsteer kit. The steering arm of the spindle is still straight, but the inner tie rod turned into an S.