I can only think of problems with such a system, and absolutely no advantages over a DI RLGS.
Anybody else notice that LWRC introduced DI guns at SHOT this year?
Anybody else notice some of the most prominent people in the industry who are behind op-rod driven designs, who also conduct high volume training? Guess what they are shooting in their courses? DI guns.
The amount of rod length, plus port pressures required to run a 7.62 RLGS op-rod system are fighting each other big time. Longer rod = more weight, farther port = less port pressure.
Less port pressure
+
Heavier op-rod weight
=
Short stroking malf-o-matic.