@jcarterKBdesign The horizontal rails need to have their X Position locked to the left corners of the left hand stile. The X Position of the right hand stile needs to be based on the width of the door
Here in my drawer component you can see how the positions of some of the elements are established. In this case the drawer box component's axes are placed so the drawer can be dropped into place at the front lower left corner of the opening and leave the required spacing.
Screenshot - 8_20_2024 , 10_36_30 AM.png