I am far from being a wood expert, but I'd be willing to bet that you're going to have floor vibrations problems with a 40-foot, 24-inch deep wood system.
Regardless of what the tables say, you should figure out how to check floor vibrations for this system.
Im actually looking forward to the vibration effects of the trusses and try to see a table that incorporate this effect ,..also how it behaves if double or tripple truss is used instead...