I'm struggling with brake balance in Imola too. Rear balance in Imola is difficult because you can't do some of the hard braking on a straight line. Generally rear braking balance is more unstable but stops you faster. On twisty tracks with not so many hard braking points I tend to move braking balance towards front (maybe 56 or 57) because it stabilizes car a lot a. Front balance locks fronts easily which isn't good for tyre wear. But i find braking distances with front balance more predictable, being consistent with rear balance is challenging, locking up rears is worse than locking fronts.
-Matt