This much-request feature has finally arrived in Revit® 2022.1!

When adding, moving, or copying a component, snapping to a midpoint between two points can be invoked!!

Adding a component:

• Initiate adding the desired component
• Right-click in the drawing area > Select Snap Overrides > Select "Snap mid between 2 points."
  
  • Select the first and second points that the element will be placed between.
  • The component is placed at the midpoint of the selected points, or if placing a wall, the end of the wall is placed at the midpoint.
    

Move and Copy a component:

• Select the component
• Invoke the Move or Copy Command
• Select the base point for the component
• Right Click in the drawing area > Select Snap Overrides > Select “Snap mid between 2 points."
  • Select the first and second points that the element will be placed between.
    
  • The component is placed at the midpoint, or if placing a wall, the end of the wall is placed at the midpoint.
    

Note:

When adding a hosted element such as a Door or Window, the Snap mid between 2 points cannot be invoked; however, it can be invoked when moving or copying a hosted element.

A keyboard shortcut can be added for “Snap mid between 2 points” as well.