As far as push button ease and doing other stuff - that kind of means having ALL the goodies in place - ie bar feeder or puller, power chuck, gang tooling or automatic tool changer. I think even the small commercial cnc
lathes don't have automatic chucks (ie microkinetics, bolton hardware, smithy, etc)
Being able to "undo" the cnc
conversion - yeah that is usually possible as the conversion process usually is an add on and drilling a few new mounting holes. I am actually considering a conversion that could best be described as "clamped on" where the Z axis ballnut has a quick release to allow returning to manual machining and for the cross slide I need to think about it some more - either retain the lead screw and deal with backlash and back driving a servo / stepper or ??? There is also the idea of an pendant and no real manual control (like on my cnc
'd mill) but it sure is nice to not have to boot a pc to turn down something simple sometimes.
Also - the slightly larger lathes (ie 12x26 versus the 9,10 or 11" lathes) are easier to convert due to slightly more room to play in around the cross slide, but you pay more for you conversion parts....
Just my 2 cents as I rambled on a bit there...