Ah, swift/obj-c snafu on my part. Obj-c methods don't autocomplete when using the dot operator.

This solution mostly works, but it still manages to be wrong for the first insert... I've littered my codebase with unlocks and I can't seem to get that first insert to size the labels correctly.

This is a frustrating side-affect, because from our clients POV, we certainly should have labels figured out after 2+ years of development.

How many labels are added in your first insert? I can try to replicate that

Likely just one at a time.

I think i found the issue where the label gets clipped when you only have one visible label. Before I start making any changes, though, I'd like to make sure that's the issue you're seeing with your project.

Take a look at the attached project. Once a point is added, the label is clipped. Once there are two labels, they get scaled down to fit the available axis label space.
Let me know whether that's the problem you were reporting. 

That looks like the problem. Thanks! :)