There is no difference in the Edit Mode Mirroring in 3.5, compared to earlier versions.
If a Vertex is slightly moved on one side of the Mesh, compared to that ‘same’ Vertex on the other side, Then Symmetry won’t work for that Vertex. If the Topology is still the same on each side of the Mesh, it might work with Topology Mirror enabled.
But I wouldn’t rely on it; use the Mirror Modifier instead.
