I just thought I should update this issue…
Khéna is now 36 pounds and there is no seat that has been tested for his weight.. I went on the Car-seat forums… the place that will make you feel like dirt if you don’t keep your child RF until they are past the limits and will help you find any solution that will keep a child RF for the longest possible and really there is nothing to be done for now… so 2 weeks ago, with a very heavy heart I switched Khéna from RF in the Sunshine kids Radian (which is one of the strongest seats out there at the moment) to FF in the Evenflo Triumph which is just more comfortable and will be good for FF until he hits 40 pounds or outgrows it height wise.
So here is what they all look like now… (Colin and Xavier are in 5 point harnesses in the Radians)