retaining walls free placing or without collision.

on mining there was the problem that excavators have not remove earth/stone from the walls completely because the mining designation is a full square the walls are half square and the placing of another wall for support of the above one was not working.
an approche like in other building games where there is no collision with the ground or certain objects or the remove of those in the place of the wall where good to have and will make the build of creative mines more easy than annoying.

If I recall correctly, it was possible until certain update to define an excavation or filling area and then place retaining walls inside with no restriction at all. Excavators simply remove the land available within the walls accordin with designations, and the common placing method used to be to put a retaining wall just between two squares. Now that's not possible anymore...