TOST vs. Schweizer Hooks on Tow Planes.

Mr. Connelly, for my own knowledge where does the 1500/1200 lb. limitation on the Schwiezer system come from. Ive tried to find a reference in the past but couldnt find one.

To respectfully add to the debate, I'd challenge anyone in favor of ousting the Schwiezer system if they feel the same way about aero tow with a Tost c.g. hook? Here the superior Tost system has been perhaps miss used and this installation has caused more glider accidents and fatalities than Schwiezer release on tow plane accidents.
I appreciate the position of the "hands off" crowd, what I'd like to see is if those in favor of banning the Schwiezer system on the tow plane also believe they should be beholden to a regulation or policy affecting the method by which they are towed in their glider (when it's their expense).
These two items would have the single biggest impact on soaring safety that I can think of at the lowest cost and highest participation level if it were either a regulatory or insurance requirement. The problem is pilots are cheap and nobody thinks it will happen to them.

-Doug