Hey Festdewalkita,
retrofitting inductive proximity sensors as limit switches to a Onefinity Classical machine is something that I consider as very good value to achieve position repeatibility over homing / shut down. And there are already two offers/possibilities for the necessary files for parts to be 3D-printed in this thread.
And the effort to retrofit them would not be wasted if somewhen the Upgrade package to Elite comes out since, as Tom has shown, they work very well with the Masso G3 Controller too.