Help setting origin & X/Y axis limits

It is just for delta printers that you have the origin at the middle (centre) of the bed.

For cartesian and corexy printers the origin is always one of the corners. There is no need to configure a centre.

You set the corner origin in [stepper_x] and [stepper_y]

You have to set the slicer accordingly.

You may have a look on this: