I have a suggestion, and I don't claim it as IP. It's yours for the taking, and I hope you make it. I'm sure I'm not the only one.
Piston systems are popular enough to warrant a market place for them and handguards that fit them. You make the best on the market, but they are a pain to use with the piston systems.
Here's a mod you should make.
From the side, a notch is cut out of the top near the gas block, making gas adjustments MUCH easier. From the bottom, two channels are cut into one so that set screws for the gas block can be reached.
Additional length could be taken off the top rail if necessary, but the idea is to leave it as long as possible while still making adjustments by hand possible.