The Santa Rosa situation is a mess, and has been addressed before. I think the HB is correct as is, based in part on a field check last summer. But I'll look into the missing waypoint on US 54. I'm in southern New Mexico right now, but a bit pressed for time at the moment, I'll get to it later.
On NM 501, I extended it based on NMDOT's online mapping, after a field check. I'll check later on the point label and shaping.
I missed the original post. At the time, I was on the road in a remote place with no Internet access.