It’s not the only one overperforming in this regard, RDY radar can only track 10 as well on the Mirage 2000-5F irl, but can track more than 10 in-game. A bunch of radars should be hammered down in this regard except for perhaps some of the ESA radars ingame.
While this document is for APG-83, I think it would make sense to make all PESA and AESA radars in the game behave similarly unless there are documents to prove otherwise for that specific radar set. (Since this capability is a result of the electronic beam steering which is inherently much quicker than mechanical steering).
According to this brochure from Lockheed Martin, APG-83 can keep tracking and updating the TWS tracks, even after they leave the designated scan pattern (as long as they stay within the reach of the electronic beam steering):
Also it appears that the APG-68 they are refering to is the first version of the APG-68 in game we have the V5 and V7 so theres probably more improvements that were made to the radar to track more targets.
Situational awareness is not necessarily for weapon employment against all available targets.
And that is very obvious.
Weapon employment requires higher quality tracks, and you can do a much more limited number of those. (since you have to update them more often)
And there is also a limitation in terms of datalink channels.
Unless I am misremembering what the lines meant (or misunderstood them in the past), APG-63/65/66/68 (63PSP is 4, Baz is 10) all seem to have a limit of 10 targets tracked in TWS (alongside N019 and N001 variants):
Tracking 10 targets in TWS does not automatically mean you can guide missiles at all of them. This is because you need accurate enough data for each target, ability to compute the required data link info for transmission, send that data to each missile (make sure they receive the data and that the data received belongs to each missile). All that has to be done while already doing other TWS stuff with a single antennae. Also, why do you need more that 6 for APG-68, you don’t even have that many missiles?
Here is a snippet from Forecast International (I know, secondary source, but using this to show you that data link limitation is a thing that exists. You can probably find more yourself with a deeper search.)
In any case, if you want to prove that APG-66/68 (or any other radar) can send info to more missiles with datalink, you will need to find a source that explicitly states that. Just “can track x targets” does not automatically imply it can guide missiles at all of them.
There is though, missile SARH guidance is done with HPRF modes only as that is the only one that can provide the required semi continuous or CWI (continuous wave, interrupted) signal.