In theory framerate should never be a problem in VR because most if not all VR systems (and/or games, I'm not sure) use this technique, which name I can't remember, where what's shown on screen for each eye is just a quad with the scene (for that eye) as a texture. These two quads are always updated at full framerate regardless of how fast or slow the game is updating its rendering of the scene itself. Essentially, as you turn your head it's just this quad that gets rotated and moved accordingly. When the game gets the next frame rendered, the quads are then re-positioned to be directly in front of your eyes once again, with the updated texture.
If the game is slow to render a frame, and you rotate your head while the render isn't updating, you start seeing this quad being rotated accordingly instead (breaking the illusion). It looks unrealistic and jarring (the more you get to rotate your head from the intended position, the more you see that it's just a flat plane), but it shouldn't cause nausea. If the game is just slightly slow (eg. it can only render at half the framerate of the headset's framerate) you probably won't even notice the plane.
Of course even this technique sometimes fails and even the quad isn't updated at full framerate, in which case the image is just stuck and doesn't respond to your head movements. If this happens very often then it can be very bothering and nauseating.
You are referring to reprojection. There are a few different variants of it, Meta/Oculus calls it Asynchronous Space Warp (ASW), in SteamVR it is called Motion Smoothing. The basic principle is the same: The panel framerate is always the same, and if the system cannot deliver the frame within the allocated frame time (for 90 Hz this would be 11.1 ms), reprojection kicks in, the headset switches to half the frame rate and "interpolates" the missing frames. This works better the closer your system is to being able to maintain the target frame times (you get more artefacting the more frames the headset has to generate), and breaks down the moment the frame rate falls below half the refresh rate. Depending on the implementation there are various artefacts that go along with it. In ED you can see those artefacts very clearly, for example on vertical lines in the HUD when your ship is rotated by the hangar floor. Vertical lines start to get "jiggly" and are not straight anymore, if you know what I mean. You can also get ghosting and blurry text. With reprojection, the rendering is decoupled from yout head movement; once reprojection breaks down, the head tracking also gets very janky, and that is
really nauseating.
This technique is actually being adapted to 2D games to decouple the game frame rate from the render frame rate to reduce and minimize effects like input lag or the problems you get when you tie physics to the (render) frame rate.
Then I'm sure you would like those rollercoaster games which move on their own with you on board.
Strangely enough I find roller coasters not so bad. Probably because it is a seated experience in-game as well as for your body. It is much worse in roomscale environments, and strangely enough in ED's camera suite
when I use the mouse. Moving in the camera suite with the joystick is perfectly fine. Probably because I have more fine control over it. Generally it is probably worse when there is less visual reference around you that moves "with you". I can do smooth motion in games like Alyx, but I need some time to adjust to it and cannot do it for extended period of time. Because of that, I played Alyx with the "zoom" movement - I forgot how it was called. Not the teleport, but the one where you do one swift move to the indicated position. That was okay for me and less disorienting as the fade to black - move - fade up at a different position. That is annoying.