Bumpsteer is not the same with a rack & pinion IFS is not the same as with cross or traditional "side delivery" steering, It's equal to both wheels in the in or out toe, not side to side movement. And bumpsteering is built into all factory independent front ends. Yes to much bumpsteering can be a problem, But with a rack it doesn't throw you side to side!!! Unless it's way to much, then it could if one tire grips the road better.
But it is a easy fix, unlike the rest of the geometry which is screwed up on most other aftermarket bought MM II front ends, made by top name companies! Which is a bitch to fix, and is blamed on bumpsteer, to cover their butts!
Bumpsteering can be fixed by moving the rack up back into alignment with the angle or by raising the arm ends higher or lower or both or by changing the rack to a narrower one. It all depends on how much he narrows it!

Instead of jumping on me......Why don't guys tell him how to fix it??? Or....Didn't you know how! At least I told him WHAT was going to be wrong!
I get it... You'd rather jump on someone, then help someone, cause you didn't know how to fix it.

Pat