I'm not familiar with the Hobie trailer but it's certainly possible to transport 2 AI's stacked on a lightweight trailer. I have modified a 200kg capacity trailer that does just that:
It used to look like this:
What is the carrying capacity of the Hobie trailer?
To give you some idea the 2" steel framework and racks for the above weighs about 60kg. and 2 AI's are about 52kg each.
If you haven't already seen it the details on construction and other trailer ideas can be found here:viewtopic.php?f=73&t=11063