that should help a bit for traction, though it seems more like a spool than a locker. Have you done any traction aids in the front yet? I dont like locked fronts and usually just do a limit slip, I have been telling people about this mod using macks swimming ear plugs in the diff, they are 100% silicone and dont hurt the gears while still allowing some slip so the truck can turn better than locked.
This rig is looking sweet, loving your creativity and ideas wrenching on a Tamiya vehicle. Wondering if you have considered shaving those arms? They look to be universal from left to right, and has nubs or mounting holes for the shocks on both sides, resulting in an unused hole on the bottom(circled in green). They look to hang down a bit, possibly something that would hang up on obstacles? Every bit of ground clearance helps!
Have fun and I hope you complete the G6!!