>By my understanding, a universe with no conscious experiences is the best possible universe by ANU (though there are other equally good universes as well). Would you agree with that?
I’d say that a universe with no conscious experiences (of suffering) is the best possible universe by ANU. If there are neutral, tranquil or pleasant consciousnesses that can’t ever possibly suffer (or change to a state of suffering), their existence or non-existence wouldn’t matter and an ANU would say that the universe with them is no better/worse than without them.
That is what you meant/thought by equally good universes as well, right?
A Buddhist-inspired answer would be that a classic utilitarian’s craving for or grasping after pleasant or “heavenly” states of existence is what causes them to reject NU or at least not be negative leaning. With modern lexicon, that may be likened to a brain’s reward function being why they reject NU, with pleasure holding more motivational salience than pain/aversion or tranquility (if the most latter can be attained or sustained).
Partially torn/Extremely injured Wrist TFCCs and later what was likely CFS or some error in steroid hormone metabolism. I would not say that either of these were ever outweighed by positive experiences. With sufficient experiences of suffering, I became an NU and no longer desire (nor do I oppose) higher gradients of bliss, unless they work in some instrumental anti-suffering fashion.