you can probe with the z axis if you require and set the home co-ordinates accordingly, but you would not use the "standard" home routine / onsceen button.... you could however change the button to run a custom macro which could then partially automate your homing sequence and setup.
limit / ome switches would be a recommended addition to you machine as they would speed up the homing process and automate it for you (without a manual routine / a custom macro).