Never checked the torque specs. Ran them on my open guns and CO guns. Hand tight with a drop of blue loctite.
I have 5 of them. Only time I've ever had an issue with the glass was on my co guns when running a 12#. Friend bought a max and ran the 12# and cracked it within 500 rnds. Other buddy running a 14, no issues.
Same with my wife's max. 12, crack. 13, good to go. Not scientific, but......