Cool.....I'm contemplating the same build. I just don't have the lathe, yet....lol.
What did you use for ball screws? I have some 5/8 Rotons with double nuts that are waiting for a home.
I'm looking at the cncforpc optical switch, or the PMDX. It appears that the cncforpc one has a remote sensor, which would be easier to manage.
Can you post some more pictures?