Are there any practical cases where this matters? I mean, the output should appear identical in POINT, LINE, or FILL mode with or without vertex colors.
Back face culling depends on the vertex winding order in your triangles; using (v0, v1, v2), (v1, v3, v2), (v2, v3, v4), (v3, v5, v4) preserves the same winding for all triangles in the strip, meaning that the cull mode itself doesn’t need to be flipped (e.g. from CCW to CW or vice-versa) on alternate triangles.