In addition to Stuka's quote:
Aquila, after looking at your 2 tracks, I don't see lasing issue in most part of TGP's FOV. You even lase backward. The only spot where I see an issue is indeed near sidewinders, and so an idea comes to me.
I did myself 3 tests. TGP on the left wing hardpoint, without ECM pod, with ALQ-184, and with ALQ-131.
What I observed is that TGP's mask limit at 9 o'clock is always the same regardless if an ECM pod is present or not.
Even if you have no ECM pod and your TGP could lase without issue at 9 o'clock, masking profile used is the one with ALQ-131 (the most restrictive). And a small safety margin is present too. Mask zone occurs a bit before physicaly crossing the ECM pod limits (or other stuffs).
It confirm the above quotes, and mask zone seems correct in regards to the most restrictive profil imposed by DCS.
So in the TGP + sidewinder configuration, the mask zone works (in DCS) as if you have an ECM pod on each wing...