[SquadSightPCS.X2DLCInfo_SquadSightPCS]
DLCIdentifier="Squad Sigh0t PCS"

Is that correct? "Sigh0t"?

Also the mobility penalty is actually a mobility bonus: the config values are positive, and are not negated in script.

Yes, I can confirm this doesn't work, the code is wrong.
The effect checks if the weapon taking the shot is also the weapon from which the squad sight pcs ability comes from. However, squadsight pcs' ability comes from a pcs, not a weapon, so this will always fail.
Presumably this was copied from a code in which the ability comes from a weapon, and then this check makes sense.
As a result, right now the pcs doesn't do anything.

It's not working and I don't understand why. I've added some `log() statements in the code to see where it fails and every time I fire my sniper rifle is see that "SourceWeapon" is always "none" so the effect code never proceeds. What does "// Attack must come from correct SourceWeapon" mean? What is the correct SourceWeapon?

yes, he really did an amazing job with this mod's mod preview / icons

Big thanks!! especially to my mate @EndlessPie49

It has a config to make it give squadsight.
On default is on only for Epic rarity

To confirm, this only decreases the Squadsight penalty, it doesn't give the equipped troop Squadsight? 🤔