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.
An amphibious Light Sport aircraft is restricted by statute to 1430 lbs. gross takeoff weight. Based upon the empty weight, the ICON is limited to 100 HP. Despite all carbon-fiber construction, the ICON A5 with typical options is going to be heavy. This will result in a full-fuel payload of approximately 300 lbs.