Actually no, I didn't see such an implementation yet.
The BW model here really is covering most of the ground properly, so re-inventing it can easily end up being a huge waste of time.
It's just one of these fundamental data designs that need to be implemented just correctly to provide the required flexibility, performance and well, correctness of data.
Guess it's the same with many other features, that are just not available on DBMS level, but on a DW level.
Which again shows: BW on HANA is there to stay 
.
- Lars