I have a few ideas, though I have no idea where they fall on the good/worthless scale:
>Instead of struggling becoming harder and harder as you do it, which is just an odd cycle of [spam-click for 2 seconds>wait in frustration for 10 seconds>repeat], timing it against thrusts could be a little more fun. I'm assuming you can time against thrusts, because the procs like aphrodisiac already seem to work that way (though its been a few weeks since I've played, I might be misremembering). So the longer it's been since a thrust, the less stamina is used. Being thrust into while trying to struggle breaks focus, and carries a stamina consequence.
I was also uncertain as to what each icon represented, but an earlier post indicated that 2 hearts was paralysis? If it's not too difficult to make a proc last past a specific grab interaction, that could be an orgasm meter. I don't remember any examples of her cumming independently of enemy action cycles, so that could be a fun mechanic. She cums, she is stunned for a little while and unable to fight back. I remember trying to get the 2heart icon to fill up was pretty difficult, so both having it endure past a grapple and having it start building before aphrodisiac is finished could make that easier, as well as maybe taking a big hit during enemy orgasm. (Potential bonus: I have no idea if it's easy for you to effect when animations occur, but adding some leg-shaking during orgasm would be a nice flavor addition)
