Eks gave the traverse crank a few twirls, told me the gear was engaging the rack entirely too tightly, and recommended shimming the apron:

Of course, he was right.
Took two 18 mil shims to make it feel right, for whatever that’s worth.
That isn’t the prettiest solution, but it’ll suffice until the ways wear a bit more, things settle in, and I can cut a proper shim to surround the bolt holes across the entire bearing surface.
You can just make out the transparent plastic sheet that serves as a chip shield around the traverse gear shaft; kudos to LMS for that upgrade.
A chip shield tube / roof over the leadscrew is in order, too.