Implementing this would mean needing a new type of chart.
So if they use this idea to lump both charts together, why not categorise full games like this?
So for example, one for S1-S3K, one for Sadv1-Sadv3, one for SA1-SA2, etc.
If they do put in this sort of "category" chart, they'd have no reason to stop at just S3K.
That said, it's unlikely that it'll happen...