Changing stats, he suspects, is not actually good for him.
Not as bad as swapping Wisdom up and down, forming new mental skills and circuits that depend on a certain kind of boosted reflectivity which then abruptly vanishes just as his brain was getting used to it. Bumping Wisdom up and down is probably literally the worst idea.
But even Intelligence going back and forth between 27 and 25 is maybe not as good for a dath ilani brain as he would have liked, in an ideal world.
It's time for a conversation that he's really dreading, and if he was significantly less calculating, or less reflective, or had more force of personality, he wouldn't be able to bring himself to say it.
He is going to try to explain that he thinks all the changes of stats are really not good for him, and then, ask Carissa for her headband... more or less for the foreseeable future. She can have all of his own augmentation items, they can spend even more money on Wisdoms and Splendours, but - if the time she's bought is going to mean anything, and if - it's considered a good thing that he holds himself together - he needs a constant stat block, and he needs that stat block to have INT 27, and there's not, really, any other obvious way to achieve that, unless he's missing something. It's not even - obvious - that it would be an especially good idea for him to take off the headband - her headband, Carissa's headband, for which she sold her soul - while he is sleeping.
...he'd tell him to get lost, but Carissa has surprised him before; she is stronger than he.