Some thoughts from Quick & Dirty prototyping on my Charger build, using a Leapers MNT-RSQD403 optic riser as QD proof-of-concept:

1. With the added length of the riser, you lose both Positions 5 and 6 with pistol braces to stay below the 13.5" limit if I'm measuring right. One your own QD conversion becomes available to replace the crossbolt, that should reopen Position 5.
2. With SB Tactical adjustable braces (A3 and A4), you also lose Position 1 unless you chop off the front 1/4" "lip" and cut a hole for the tube and bottom keyway in the brace's rear. (About where the SB logo is.)
3. A SOPMOD stock fully collapses into Position 1 and will lock in folded position, but the saddlebags mean it will be a few degrees off parallel to bore-axis. The more you extend the stock before folding the closer you can get.



This pic has brace and stock "normalized" to correspond to both being in Full Collapse position. You guys have a solid product, and if BATFEces doesn't bugger us on pistol braces, once I pass the kidneystone of stocking up on soon-to-be-banned-in-WA mags and you roll out the QD conversion I can easily see myself buying a second for this project's stock assembly.