Oh my goodness thanks. I am using a SPA version, which must have been translated by the enemy. (For non-Spanish speakers: every single folder and object name in attached screenshot is gibberish.)
I'll have to keep USA open all the time, look up stuff there, and then try to make sense of how things got messed up into SPA.
This will have saved me a lot of trouble.
[Edit: the 'nested' fitting is the piece needed for splitting the duct into two.]