Hi!
Here is my interpretation of ruka’s bicycle transport system:
I have adapted it for my 29er municycle, but the basic idea with the Ortlieb bike bag is the same. You can buy the mounting parts as spare parts on the Ortlieb homepage. I paid about 35 euros. The rest (screws, wood, etc.) I had at home in my workshop. The construction took about 2 hours. The system is super stable and works perfectly on my e-bike. Thank you ruka for this cool idea!
Looks like another nice Ruka Rack.
Very welcome! 
This thread and it’s photos, and photos that @toutestbon recently posted of his bike trailer that he used to transport items to/from the post office, got me thinking.
A quick search on FB Marketplace allowed me to find and purchase a bike trailer that can serve as a “unicycle trailer”.
I have used it to make runs to the grocery store, but haven’t yet used it to carry the unicycles to the closest Muni trails.
I can easily strap the unicycles to the trailer frame to keep them from moving, but I plan to create an additional frame/cradle out of PVC that will keep them from moving, using one strap to secure each seat post.
While the entire setup is not space-efficient in use, it can be efficiently stored.
Nice bike