We will warranty our wheels for the same weight as the Dahon frame is warrantied: that is, up to 105 kg (230lb).
In fact the wheels will take more weight than that. But you are right that one size does not fit all: the wheels we are offering on Kickstarter are designed for a median range adult. So they are too stiff for a very light adult or a child (won't get much benefit) and if you are significantly heavier than 105 kg you would need us to make you stiffer springs in your loopwheels. We plan to do that in the future, and to supply a range of loopwheels suitable for lightweight and heavier people, but sadly through Kickstarter we are only making the one median weight available.
I'm really sorry that might stop you pledging via Kickstarter. But if so, please don't give up on us - we will do stiffer loopwheels for hefty guys in the future. Stay in touch!