As u say, a new twist on an old theme, Very shy on detail, meh.
I guess its 8 lane - must be if up to 7GBps, which seems optimistic vs other raid ssd benchmarks.
But yeah, fascinating and potentially useful in niche tasks.
this el cheapo 4 pot sata card (marvell chip?),
https://www.amazon.com/Vantec-4-Channel-HyperDuo-Technology-UGT-ST644R/product-reviews/B00EA0WMOS/ref=cm_cr_arp_d_vote_lft?ie=UTF8&voteInstanceId=R3S9XSOC22SZ4T&voteValue=1&csrfT=gMy8QnVk8BJ7WySk2CMXh1pnbmtcW8MwMuxGEtMAAAAJAAAAAFktrSxyYXcAAAAA&
has a similar Hyperduo feature.
I have one, and some superseded sata ssd & HD drives, & may play with it for fun.
2 combos that appeal are:
a raid 0 pair of sata ssds as a ~1GBps maybe read and write temp files drive
and also, an ssd, similarly to MSI, caching a raid 0 pair of HDDs also on the card. Its the best of both worlds. ~0 access times on popular and small files, automatically resident on ssd, yet get passable 300MBps sequential from the raid 0 HDDs for bigger files. There seems something zen about both elements being similar speed once HDD raid is reading data sequentially. Raid0 also allows decent partition sizes by doubling capacity.