My statement was entirely consistent with the separate condition that partner awards must follow routing roules. Not sure why you quoted me out of context and cut out the second part of my post, since the second part was the entire point.

The second part said "All partner awards are either available at low price or not at all".

If xxx-BBB-yyy is within the routing rules, it will be available at the "low" price or not at all. There is no such thing as partner awards pricing at anything but "low" level. Sometimes the low one-way price is doubled to roundtrip price for that one segment if considered by the pricing engine as a one-way rather than part of a roundtrip or open jaw.

Perhaps you are touching on the fact that if xxx-BBB-yyy were not permitted by the routing rules, it would be broken into xxx-BBB and BBB-yyy, which could price as two one-ways (round trip price for DL) depending on the itinerary and thus increase the DL miles required?

In the above case, I would not characterize it as xxx-BBB-yyy being available for more than the "low" price on the DL award chart. It is more accurately described as xxx-BBB and BBB-yyy being individually available for the "low" price and (perhaps, depending on the itin) having the price for each segment doubled to that of a "low" round-trip since DL does not price one-way awards differently than round-trip awards.