[Request]: List<Interface> and List<Abstract> provide a mechanism to modify concrete type.

Description

I'm working off the master branch so my apologies if this is already on the radar.

Currently the + key gives you the option of selecting the concrete implementation, however, once you've selected it the only mechanism to remove it is essentially Pop()ing the element with the List-level -.

Ideal fix would be something like a right-aligned modification button to element list, but honestly just being able to remove a list element would be a pretty significant improvement.

Benefits

Current UI is clunky as you have to move your undesired element to the bottom of the list and pop the list.