BD working BRS-ZRH would have the benefit of a potential codeshare with LX (through the LH group), and more of that feeder traffic that seems to be helping FRA and MUC so much. It's also fairly comfy for an E-145 (shorter than MXP, about the same as MUC)
LX's short haul network through Europe compliments LH's well (and can be a bit cheaper), and their long-haul service beats LH's hands down.
BRS-FRA is going 3x from S15, and both MUC and FRA get Saturday morning departures, so I hope that's boding well for that current strategy. Maybe the HAM frame could work BRS-ZRH in the midday slot?