I want to align vertices along the z-axis to be in line with another vertex. I know about S-Z-0 and pivoting around the active point, which aligns the vertices but deforms the edges these vertices are currently on. Like when pressing GG, the vertices slide along their edges, but I also want to align them to be at the same Z position as some other vertex.
The first image is the object, and the second is the side view. I want to align the highlighted vertices with the row below (same Z value), but I want the selected vertices to slide along their edges.
I could align the vertices by sight using GG, but is there a more precise way of snapping the vertices into place?