Yup, you're right, this is seriously old news.
It's also been NOTAM'd for a bit, and has (infuriatingly) been the subject of a 20-second extra bit on the end of every ATIS broadcast at LCY. Even when using rwy 10.
Virtually every time we are lined up on 28, a HDG flag pops up, but taking a moment to re-align the ADC fixes the issue. OK, the XP may have a more fragile system, and while it's not really clear to me how the problem happens after getting airborne, re-syncing compasses is something that most pilots have been doing occasionally since basic training!
Can the XP not be reverted to magnetic reference until the clever electronics can be re-aligned?
CC