When a pattern gives a measurement from the cast on … do I measure from the cast on to the bottom of the needle (so I would not be including that last stitch) or to the top of the needle?
Measure to the bottom of the needle.
salmonmac’s answer may be right, I don’t really know. But I just wanted to point out that it is not a big worry. Unless your needles are pretty big it doesn’t make much difference. I have done it both ways and never found it created a problem. I try to be consistent within a project anyway.
I agree on most things that little bit doesn’t matter. Just be consistent if you need two things the same.