I went for practicality over posability and binned off the charging handle. No more HK slap, but a fair bit more room in the tube.
Also, I rear wired mine, as I couldn't be doing with all that fiddling around at the front. There's room to run wires behind the gearbox up to the tube. Deans connector, of course.
With all of that done, I can actually get a 116mm x 17mm x 13mm 7.4V lipo in there with a small mosfet as well.