525i 23.98 is listed as an "intermediate format only" because it is not an "over-the-wire" format and frame rate. This means that video monitors would not be able to receive this format and frame rate (they expect NTSC video at 525i 29.97).
You could elect to use the AJA Control Panel to configure a conversion from 1080PsF 23.98 to 525i 23.98. You would accomplish this by setting the Primary Format in the Control Panel to 525i 23.98 and the Secondary Format to 1080PsF 23.98; incoming video would be downconverted if the source was 1080PsF 23.98. (Note: you may need to adjust your Capture Presets and Device Control Preset accordingly so that the timecode values in the recorded file accurately reflect the source timecode values.)
If you need monitoring from the 525i 23.98 video, the KONA 3 can upconvert the signal to 1080PsF 23.98. There are even Easy Setups for NTSC 23.98 video supplied by AJA as part of the Additional Easy Setups.
If you have additional questions, feel free to contact AJA Technical Support for assistance.
AJA Video Systems
+1 (530) 274-2048 Intl.
(800) 251-4224 US