Did you progress to mount the B&W case onto that kit? If so, how does it hold? Did you need to modify anything?
In my case the Brompton + B&W case + attachments already surpass the airline 23kg/50lbs so I am not looking what to add but what to subtract.
My purpose was to have a system that I could set up to match what style of riding I would be doing,I like to travel as light as I can and did not want to tow a trailer every time.I use the case for shipping the bike and then set up the trailer for the ride to motel, hotel or camp ground.Origami's trailer is to narrow to lay a B&W case between the wheels,so I just put my carry on backpack onto the trailer frame and put the hard case on top of that and strap it down almost three inch above the wheels.It rides well depending on road conditions,etc ,average speed 10to 11mph.I have seen many folks do the same and talking to them they are satisfied with that type of set up.
If you do want to tour with the B&W attached to the frame system you would need to use a one with wider wheels then the Origami,but the Origami is super light and when everything is packed it comes out just under the airline limit. Also,if mine were to go over the limit afew pounds I would just remove my telescope seat post with saddle and stow in my backpack along with other stuff i could cram in my backpack.
Also for those who wish they could just put the B&W onto the bike itself for that quick trip to and from hotel to airport or train station,the answer is yes it can be done and it can be done either front rack or rear rack.I've put mine on my rear rack strapped to the bike cross ways in the vertical way and ridden up to fifteen miles along the beach where I live in prettygood wind.The bike rides well once you get the hang of it.The case does not create much drag going inot a wind and on the reverse trip with a tail wind you fly.
I have seen a quick video of brompton rider in England with his B&W case some how strapped on the front luggage rack at almost a 45 degree angle lean to bring the top edge of the case below the level of the handle bars so he could still steer properly.He did this in a crowded park while also holding another riderless brompton intow with his right hand and steering with his left. Show off!