Ferrata harnesses (FH) can be probably safely used also for climbing, as stated in another post.
However, I am not sure how to use the reverso with FH.
This is because in a usual FH,
the belay loop is rotated by 90 degrees,
w.r.t. the common climbing harness (CCH).
This will make the reverso slightly flip accordingly and therefore not facing the wall, but rather the side of the person belaying.
I am wondering if this is really a safety issue and if there is a technique to prevent it (like for instance using a locking-quick-draw, that would allow for more flexibility and therefore also for a reasonable angle w.r.t the wall - ~90 degrees)