I think the Saetta handle could be a very good option - but would need to confirm how large the offset really is. I think I know someone I can ask, just for the sake of knowing. As mentioned, when I tried to measure it on the drawing, I got a 4-4.5mm value which is very, very close to the Mirage. And it should give you that extra bit of space to beef up the thin walls.
I don't particularly like the line release but if that white grip is detachable, I think it would be easy to modify the grip of that handle, too if so inclined.