Serving you piping hot takes on matters high and low!
If you haven’t already, you really should read Wijesekera. His chapters on vinnana, kalpa, yaksa, and others are equally interesting. He was from that generation of scholars that was widely learned and took mythology seriously.
Not unexpected, as they would tend to follow the rationalizing interpretation, as of course have pretty much all modern English translation. But still good to see what they have.
For the record, Divy on this passage (which is likely the same or similar school I think?) has:
mātā kalyā bhavati ṛtumatī
For utunī/ṛtumatī see my former essay.
Anyway, it seems hard to get that Chinese sense from the Indic texts.
This is of course a literal rendering of gandha-.
DDB is helpful here. Given that 香 = gandha then likely 陰 = -arva or similar.
The DDB entry gives Sanskrit abhra as one rendering, which is pretty close. In Sanskrit, abhra means “water-bearer”, cloud, rain, which are all commonly associated with the Gandhabba.
It’s interesting that they managed to squeeze in two accurate, unrelated, yet common features of the gandhabba into one phrase.
So it would seem the literal rendering of 香陰 is “fragrant cloud”, or perhaps “the spirit of the fragrant cloud” (?).
Indeed, it seems quite loosely adapted from the Indic. Worth noting that, so far as I know, the Indic versions are pretty consistent.