there are several things that can be done to limit closing of her eyes.
one of the things to work around is the wincing, because she closes her eyes to make the wince.
she winces when she coughs, swallows, vigorous throating, and intro throating; making wincing a difficult thing to prevent.
i have been able to hack around quite a bit of that (hack being used to describe the questionability), by essentially passing her out initially, and emulating her being awake. combined with some vigour max level adjusting and a certain intro flag setting, the other winces can be prevented. but this also means she doesn't swallow or cough (and some dialog popups will be skipped). however, this does give an android-like behavior.
if the desire is to only prevent the passout features such as eye rolling, eyelid dropping, and passing out when throating too much, this is easy by controlling passOutFactor.
i haven't done much with iris control yet; been doing some mingling to get that quick eye roll effect from final fellatio.
anyway, i was curious if i was heading in the right direction. it is better to know the details of the goals in mind.