Retaining wall placement overhaul

Currently placing retaining walls is somewhat tedius process. It would be neat if there were improvements in the system where, for example, you can build long strech of retaining wall at once (kind of like with belts), instead of having to place them one by one.

As a bonus, a detailed mode would be cool where you place a spline that you adjust as if they were bezier curves and then the game would interpret the result. Although this sounds like a cool system, I honestly doubt it is of that much use.