Single point threading problem

[Mayhem]

I thought I was doing well with leaving the halfnuts engaged, even though to shoulder was approaching fast and the lathe takes a few revolutions to slow down. Had to throw her into reverse a little soon on a few occasions. Would have been good if I had made the spacer rather than making a mental note to make it

Now I find out that the dial is suppose to stop turning when the half nuts are engaged, I'm even more annoyed with myself for not noticing (or figuring it out)