Hey Dave, no need to add the double frame rate comp to a new comp, just render out the double frame rate comp at the original frame rate with appropriate fields.
Also you mention that you can see incorrect field interpretation in the comp panel by stepping forward one frame at a time… I haven’t been able to get this to work, what’s your secret?
The technique I use is to OPTION/ALT double click on the footage in the Project panel then hold down the COMMAND/CONTROL key and use the left/right arrows on the keyboard to step through the footage.
Best,
JD
John Dickinson
Motionworks
http://www.motionworks.com.au