I thought the angle of the turbo was supposed to be at a right angle, to keep the thrust bearings from wearing out when not on boost?
My old vw polo had a slightly tilted turbo as well (before i knew about it), not as much as your bmw though, but 7 months later and 10.000km's, it was absolutely knackered. It was a OEM turbo from an Iveco Daily 2.8 - so not a bad turbo either.
I've seen quite a lot of subarus with tilted turbos, but all of them used ballbearing turbos when doing that.
Hope yours work, i'm in the process of doing a m50 myself, and i've been thinking of placing my turbo same place, and just make a huge dent in the hood. Because racecar