You can send just about any AR10 barrel to D Wilson to be converted.
I’ve owned three SP-10s and I think 5-6 LMT MWS and MARS-H. A few SR25s as well from K1s, APCs and between.
Landed on the LMT again after trying those platforms due to D Wilson ARCA adapters, being able to just get the upper and lower then build the things out exactly how I want, actual monolithic upper, barrel changes for if I want to shoot 308 or 6.5 for myself.
You can also send your barrels to D Wilson for gas blocks like a SA adjustable and many more.
One thing I do like about the MRGG-S are the gas ports and overall just the counter sink they have on them.
That’s just me though. Your mileage may vary.