Lol funny. We must have talked to different people. I was told 15-20 ft lbs as well but that loctite is recommended if keeping it on permanently. At least they got you fixed up with another sight!
I did the first one at 20 inch pounds with blue TL and stripped one side. Did the second at 15 inch pounds with thread locker and it was fine.
Hopefully it NEVER moves. That's what I was going for haha