>>I then rendered without the deinterlace filter and it still looks good.
Did you try another field order in deinterlace filter?
>>I see no flicker or interlacing in FCP
Interlacing MUST be visible with HQ timeline settings and 100% canvas size. You see no interlacing??
>>Do you have an output file or screen shot that shows the problem?
I can record screencast but it takes time…