For some of my carves I only need a 1/4" endmill to cut. However getting the right position on that large bit is tough. In those cases I like to put a V-bit in to use the point for alignment then swap it out for the endmill. Unless there’s a 2nd stage carve in the project the Lock Motors and Unlock Motors options are not displayed. As a workaround I’m making everything a 2 stage carve just so I have the Lock Motors and Unlock Motors option.
Another use case for having the Lock Motors and Unlock Motors option is that I’ve had multiple cases after setting up a carve and the gantry is accidently moved when putting on the dust shoe. More than once I didn’t realize that the gantry had moved and it messed things up.