Strobing

That is essentially what the low persistence function @72Hz and 75Hz does, right?
If that isn't good enough for you wait for the consumer version.

Inserting black frames wouldn't increase comfort because doing that every other frame would give you an essential refresh rate of 36Hz and 37.5Hz.

The study suggested that strobing at a frequency of 4 to 8 Hz helps reduces nausea, this is far below the low-latency related darkening of the screen at 75Hz. I want to experiment with strobing at the study's low frequency when the player moves or turns. I wonder whether the fact that I don't get a full dark or full bright screen but vertical slices means that all the time, even in other demos, my Rift display is mixing slices from different frames, which might be one reason for nausea.

I get the impression this study is really old, back when VR was in the military/agency niche.

They don't seem to try to counter motion sickness from realistic scenarios which can make you motion sick in VR, they try to avoid motion sickness from extreme circumstances which do not even occur in reality.
In that regard it accomplishes something: It discretizes motions so that acceleration is not perceived, de-coupling the users visual sense of acceleration from the environment. But strobing would absolutely break immersion in any case I can think of which we realistically have in a game.
What might be helpful however is to stobe the display in cases where short motion sickness generating impulses might be expected, cases where positional tracking is lost, steep frame rate drops, etc. "Virtual Blinking" in a sense, to hide that moment from the user.

There is something similar into the general direction of this approach they were using it for: It's called VR Comfort Mode, a control scheme for first person environments where rotational movement and acceleration occurs in discrete steps.

I agree, there is definitely an impact on immersion from strobing. But I get sick from moving and turning, not just in extreme situations, so I would like to have a number of options that can help reducing nausea and that are used only when you move or turn so as to minimize the impact on immersion. I already have a few options in my experimental demo, but I am interested in adding strobing not only because of the study but also because it seems to be a way to see whether the Rift's display is showing information from one frame only or whether it somehow mixed several frames, which might show a problem in the setup or configuration.

Btw, thanks for the link to the video of comfort mode. I tried that as well but I think strobing might be a good alternative option to have not only for movement (as opposed to turning only), but also because it might be more immersive to some: strobing light can happen in real life, whereas in comfort mode you teleport yourself into a new orientation.