Unfortunately there isn't much we can do about AA since it's not predicable. There is no ST or modification to it that will eliminate it. The only thing that will is to turn it off in the game you are playing.
AA is predictable and measurable, when it's effect is being applied is what XIM can't distinguish.
There is no need to eliminate AA, you can't turn it off in most games anyway and even if you could this would put you at too much off a disadvantage compared to a controller user, XIM won't make games feel like PC games when AA is turned off so there is no advantage in doing so.
What XIM could do much better at is achieving it's aims in games with strong AA without the need for high sensitivity (which means less precision and goes against one of the aims/advantages of the XIM) or acceleration via boost/ballistic curves (which goes against one of the selling points of 1:1 aim - as this is not achieved in games with high AA).
The whole premise behind Stv2 was the increased precision / extra granular aiming which sounds great in theory until you remember that console games are designed for controller use i.e. an aiming device that is the opposite of precision - hence why SA3 was voted the best SA build - the less granularity/precision of Stv1 works better for lower sensitivity players in games with high AA - this is why it was better than the aim smoothing attempts of some of the other SA builds, less granularity is the solution not aim smoothing which is too artificial and something from which muscle memory cannot be developed.
The SA development work is a major step to understanding how the XIM could better handle games with high AA and achieve it's stated goals, but this work was never seen through, which is a peculiar choice IMO given the two main things that stop XIM achieving it's goals (1:1 feel and not being at a disadvantage to a controller user) are low turn speed cap and aim assist. It feels like XIM development has been stagnant for a fair while now and canning the SA development work part way is disappointing.