I should have been more clear. Too much catalyst dissipates with an acrid, almost vomit type odor, often accompanied by a pinkish color shift and/or haze. This is a different smell than the normal outgassing of formaldehyde. In my opinion, companies that use a diluted catalyst are just trying to sell more product. A gallon of catalyst at 3% lasts a lot longer than a gallon at 10%. 3% ratios are not difficult to measure with reasonable accuracy.
Crew weight. There is a wide range of crew weights that is competitive in the Viper 640. The average of all crew weights at the 2015 North Americans: 550 lbs. Crew weights ranged from a low of 490 (#10) to a high of 650 lbs.
Such a low PIN weight requirement simply does not make sense for a diesel 3/4 ton pickup as a tow vehicle. I can understand a newbie thinking that dry weight is the weight to consider, but not getting so confused about PIN weight. Buffalo, the critical weight to look at is a 5th wheel's GVWR - Gross Vehicle Weight Rating. With your truck anything with a GVWR under 12,000 pounds would be fine, and you can probably go up to 12,500 - 13,000. This covers the vast majority of 5th wheels. The two current best 5th wheel lines with GVWR's under 12,500 pounds are IMO Crossroads Cruisers and KZ Durango 2500's in that order.