hey guys,
here is the workflow that worked for me, which is basically what Stephen recommended + the A.I.C.:
1. Convert to CBR using Quicktime Pro. Open each clip in Quicktime, do an Export to Quicktime Movie with the Codec as Apple Intermediate Codec (720p60 preset), at Current Frame Size (1280×720).
2. Open clips in Cinema Tools and Conform to 23.98fps.
3. Open 1080p24 timeline in FCP and drop the conformed clips into the timeline. (Click “No” for “do you want to auto change settings”). Then render and export one by one. The resulting exported clips will be conformed to 23.98fps, will have smooth slow motion, and will be 1080 so they’ll edit easily in a native 1080p24 timeline.
hope that works for ya.