In the majority of cases, the video export framerate should export exactly what you want. I sometimes find when exporting massively huge document that if I overshoot the framerate and retime the video, I'm more likely to get higher frame rates when importing into a video editer and slowing it down.
If your goal is to place a video export into a 30fps framerate video, then 30fps is a good export setting to use. In some cases, you might have some dropped frames which is where the defaults write com.tumult.Hype4 videoExportFrameDelay .5 terminal command comes in.
So if you have a 30 FPS export from Hype, and you want to get it to fit into 25FPS as @Aqueum sounds like he's trying to do, you would retime the 30FPS Hype video export to 83.3333% in FCP. But it sounds like FCP doesn't want to allow that much retiming accuracy. So using a multiple of 25 (50 FPS, maybe?) would let you divide that framerate in half, instead of 25/30ths.