The key is going to be a mounting system on the outrigger that is easy to construct in the workshop and assemble for use on the water. The sketches above show a "T" mount just as a concept. But a more supportive "wedge" type set up might be more appropriate. Distribute the loads better.
I was hoping to have the beams constructed of just a straight pole for simplicity. But looking at the design, that might force the outrigger to be really oddly shaped. Might be easier to come with a generic outrigger and then design the beam shape for each hull.
By the way, for you "purists", I'm avoiding using the terms "aka" (the connecting beam) and "ama" (the out rigger float) to describe the parts so I don't confuse myself or others.