Been a long time, hope you get better advice. (Havne’t done this since I threw away Infini-D, about 8 years ago!)
I think what we used to do was pretty simple: bring the 60fps into AE, interpret the footage as 30fps, and set the field order to your output needs.
I think you experiment on a short clip that has some horizontal movement of high contrast objects. Be sure to read up on the section in the manual on how to view individual fields in the work area. but you also want to render some tests and view them carefully on your output device.
bogiesan
This is my standard sigfile so do not take it personally: “For crying out loud, read the freakin’ manual.”