I had a partial case head separation using a 1.8oz buffer

[LRRPF52]

I used the 1 ounce Taccom Ultra Lite Weight buffers in my 16" 6 ARC with MLGS an adjustable titanium carrier. They worked great but I bailed on the whole system since the gas screw on the carrier would wander towards less gas. I'm guessing I had the gas open about 30-40% when it was dialed in. I'm sure the buffers would work fine on a .223/5.56. One downside though is that there can be feeding problems if you jam the mag against a barricade or bag and the mag moves in the well and tilts the cartridge nose down slightly. There may not be enough inertia to push it into battery and the round's nose can get caught up on the extension.

Port pressure is less on MLGS vs CLGS, which allows more lock time on the action so pressure can subside to allow de-obturation against the chamber walls (spring back).

A problem with lower carrier mass is as you experienced, where lack of reciprocating mass doesn’t fully strip and seat cartridges into the chamber in various conditions in the field.

I blend, de-edge, and polish my extensions, trouble-shooting them to make sure the upper receiver’s feed ramp roots aren’t deeper than the edge of the barrel extension’s feed ramps.

It takes a long time to do if an extension is too proud of that junction.