Here's how it looks like on the scope, yellow is FSYNC and cyan is STROBE (connected with a pullup resistor, so the strobe opto closing pulls it down to 0 V), starting the camera with the settings listed earlier:

Enabling manual exposure of the right eye right_r_set_man_exposure
(for some reason, adjusting the left eye has no effect) allows to vary the exposure duration. For example, here right_r_exposure
was set to 5000 (5 ms):

Weirdly, toggling right_r_set_auto_exposure_limit
on and off (while auto exposure is enabled) with right_r_autoexposure_limit
set to a low value resulted in a persistent change of the strobe signal:

I played with both the exposure and the ISO while manual exposure was enabled. The image remained black at all times (I did check new frames were being published).
How do you suggest we proceed?