Confirmed in 2.5.4.12 and 2.036. This is a show-stopper. Each Plas-D eliminates one ESG of each radius it encounters! A L-BCH with ESGs active at radius 0, 1, 2, and 3 will lose all of them to an errant Plas-D. If It has 4 ESGs at the same radius then it only loses one.
Additional Plas-D weirdness: Plas-D are the only torps that can be degraded by Heavy Weapon fire. Theoretically only phasers can weaken plasma. I shot a Plas-D out of the sky with 4 Overloaded Dizzys. Using the 4:1 reduction that works out to 40:10, which eliminates the Plas-D. I've not yet tried other DF Heavies or seeking weapons.