Taller retaining walls

I think there should be more tiers of retaining walls in the research. My idea has three tiers. The original, medium, and tall. The medium tier will be soon after steel research making the retaining walls out of steel instead of iron. The last tier would be made of titanium instead of steel. I also think instead of concrete brinks there should be a cement mixer truck to pours the cement on the built frame of whatever you are building (retaining walls in this example) allowing it to harden and make the wall much stronger than it would have been without poured cement. This multi stage construction could be cool for buildings that need to be a lot stronger. Last note. I think the two tiers of walls in my suggestion should have an adjustable height, allowing you to build retaining walls with whatever is more convenient

Already requested. I suppose they do want people to try find other way than this easy sollution though. But i do expect redesign of retainning walls in the future, as you currently must build them manually (at least you can drag-build them in one direction now) and it is hard to change theirs shape.

It just needs to be possible to build additional walls on top of containment walls.
It would also be great to add truss‑like structures to allow the construction of elevated buildings.