Deep curbs for terrace construction - the slope is incorrect

You want to cut 2x4m deep curbstones with the diamond blade in their installed state at a decent angle? In my opinion, not possible. How well did you concrete those things in? Normally, a manageable fillet is enough to fix them. Sure, it's no fun to tear those things out again, but in my opinion, it's the only right solution.

What does the gift-giving situation look like currently? - Just post a picture...

Exactly, pictures say more than words ;)
I stretched a string and placed a leveling rod - both in the water - so you can estimate the mess.

I agree with apokolok. Rip those things out again and do it anew.

Right, pictures say more than words ;)

Well, without words rather "so-so" :-(

Are we looking at these stones from "inside," that is from the terrace? - so the substructure isn’t in place yet, only this "edge"? - then I would be for "resetting" them.

I think it’s naive wishful thinking to get a surgically precise edge with the cutoff wheel there. Apart from the guidance disturbances caused by inhomogeneities in the material structure: you will hardly be able to avoid chipping as well. In the end, the things are botched, you have to reset them anyway, also turn them over, and then of course slope the bottom so that the top becomes straight. That won’t work.

Are we looking from the "inside", i.e. from the terrace, at these stones? - so the substructure is not yet in place, only this "edge"? - then I would be in favor of "resetting".

So far I have poured and compacted the mineral concrete. I would have to dig it out again from the inside with a pickaxe and shovel. :-(

So far I have placed and compacted the mineral concrete. I would have to dig it out again inside with a pickaxe and shovel. :-(

I only see gravel there, and at the lower edge of the stones something light gray that could be foil or something solid ... somehow a bit of a guessing game ...