[Ali-Pacha]

It works, with old Athena Ultrashift as well as with more recent Athena Powershift.

The return spring of the post 2015 Chorus RD is far stronger than the one on Athena RD, so it feels way harder on the shift lever, especially on the first cogs, and you need to be frank on it and fine tune the cable to get perfect shifting without hesitation. It can rarely occur in the middle of the cassette jumping to the next bigger cog, but nothing different from what you get mixing 10s generations, which may have different spring tension within the RD.

The strong feeling reminds me my 11s Centaur, which also feels harder on the lever. Seems legit from a generation standpoint. The most recent Athena Powershift feels a bit better suited, as if they're a bit franker / Campy-like, where the old ultrashift has a bit of the Shimano-like smoothness.

I also assume a narrower guide pulley axis (let's say 12s and not 11s) could also improve the thing, as the cage will better push the chain. It works slightly better with a Shimano chain + cassette ensemble, as the ramps of hyperglide tech are from my experience more efficient than the ultradrive chain + cassette combo from Campy.

Another observation : the trajectory of the guide pulley is different, allowing to clear bigger cogs.

My 2 cents here.