Again, I know nothing, but...

With ~10% of each end of each beam socketed into a well fitting taper, how can they wiggle?

Then one only needs to hold the hulls together. If the taper is well chosen, it may be a bit hard to get them apart.

The original el is an experimental platform. I don't know how it was done, or is done, but there are pics on harryproa.com that show wood block wedges that look like they hold the beams in place. Perhaps that was used at one point.

http://harryproa.com/wp-content/uploads/2012/01/Elementarry_14.jpg

Rob speaks often of his love for carbon tow, which he uses in many very neat ways to put hard points and attachments where ever he needs them. Zoom the lee hull top in this pic.

http://harryproa.com/wp-content/uploads/2012/01/Elementarry_06.jpg

So, if you can put a carbon loop or hook wherever you want, well, it's lighter than bolts.

Rob seems to take Chapman's 'Simplicate, and add lightness' as the first commandment. So, I expect something simple and light.

I don't see any bolts in Robs designs.

Also, your design would be simpler with straight beams, I think.