nominalFrameRate is 30 for 240 slow motion video

I am currently working on a SwiftUI video app. When I load a slow motion video being in 240 IPS (239.68), I use "asset.loadTracks" and then ".load(.nominalFrameRate)" which returns 30 IPS (29.xx), asset being AVAsset(url: ). And the duration in asset.load(.duration) is also 8 times bigger than original duration. Do you know how to get this 239.68 displayed in the Apple Photo app ? Is it stored somewhere in the video metadata or is it computed ?