Beware of the 1-frame video delay. Here is an email response from AJA:
Setting the video playback to 1080i29.97 and the Kona secondary format to
525i29.97 is a valid way of downconverting.
One word of caution: there is a 1-frame delay for video only with
downconversion; therefore delay the audio on the FCP sequence by 1-frame.
Some editors are still okay with a 1-frame delay but I thought I should
mention it.
Best regards
Rudy
Rudy Van Kol
AJA Video Technical Support