Exactly. My LBS installed a generic 39T only to find it shifted poorly. They realized the “switching ramps” that come with Gossamer chain rings were missing. The problem might also include incorrect or missing lift pins and gates, as you say.

They’re in the process of locating a ring that has that and will work well. I had thought simply ordering a Gossamer 39T for the FSA triple would be the solution, but easier said than done.