No it doesn't. Unless he wants to crank in a screw with the wrong head type on it.
The MagPul PRS comes with the correct screw if you are not using an extension, a flat truss-style head that is slotted. The DPMS extender kits come with two screws of different lengths, with flat heads that need to be countersunk.
Another issue people have been having with stock extenders is the screw not being vented...creates just enough back pressure in the system to piddle with the reliability.
You've fixed the issue with the length stopping the rearward travel of the buffer, hence the BCG not being able to engage the bolt stop.
If you find your LAR-8 still isn't cycling reliably, take your 1/4-28 stock bolt down to the machine shop and have them drill a hole with a 44 or 43 drill bit.
I chased this issue quite awhile, when I changed out magazines, my gas block, and the stock all at once. The screw length was easy.
Other people mention the screw issue on the reviews here: http://www.brownells.com/rifle-parts/receiver-parts/buffer-tube-parts/buffer-tube-hardware/ar-15-m16-buttstock-extender-prod5559.aspx