That trap uses a pan & dog similar to the posi-trip system. Pan tension is achieved through the geometry of the components. Not with a mechanical connection (nut & bolt) that creates resistance to movement.
Bending the dog /cross piece is the only practical way to change the pan tension.
Just like any other trap you should check the pan tension and adjust, after the trap have been prepared in the manner it will be used.I wouldn't take advertised figures as gospel just because someone wrote them down.
Here is a link to an archive page that describes the pan/dog system fully
http://sullivansline.com/forums/ubbthrea...=true#Post25456