I mounted QS8s on thin cheap wood panelling without studs. Worked fine, but I used more screws than Axiom provides in the package... try to get at least 4 or 5 screws in and make sure you don't drill the hole for the wall anchor too big.

The T-bracket is nice in the sense that it pulls straight down, not out, and drywall is pretty strong as long as you don't pull out.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8