Yeah I thought about that. Were you able to mount it using the Rotopax plate and bolts? I tried and couldn't get it to quite fit, and I think from your picture it looks like the Rotopax is strapped on. I think it's a good solution but still thought everything together was a bit wide and the Mosko Moto was essentially just the cost of the rack so it made sense to me to swap to a rackless solution.
Correct, I just strapped it on with bungees. I have a couple of ideas for a better mount, but it hasn't been very high on my list yet.