I'll post the Vincita dimensions.
Makes sense.
Weight-wise I begin to think that this does not stack itself up well. I doubt that the BF wheels with their bulky plastic offer much savings in weight compared to 16", but I will weigh them just in case. The small Y trailer with 16" weighs 6.7kg and Vincita weighs 2.5kg. With the Brompton and some junk on it this starts pushing airline limits. However, it is not quite out of competition so it can be worth pursing just to establish the option.
What is shipping prices compared to overweight prices? If you have a place to ship to you could ship (by post or other source) to your destination in advance instead of paying the heavy fees. Just playing with ideas.
Also if this is something you would do often maybe getting lighter 12" wheels?
Are the no puncture tyres (foam) lighter than the rubber tyres and tubes that are more and more available?
I have been thinking for some time that if the small wheels on kick scooters (or the A bike) can take the beating they do should they not be able to be used on a bike trailer- at least on paved roads? I tend to look at bags for sports equipments and other suitcases with that size wheels to decide if the wheels can be exchanged for better ones and then pull behind a bike. Not suited for world touring but if you want to go from the airport to a hotel- or a friend- maybe. I bet it could be noicy.
Can you buy carbon wheels in 12"? I bet you can. There is a lot going on in the "sports equipment for disabeled" area that we know nothing about (I`d like to dumpster dive outside theyr offices
.
One more thing: You say the small Y frame with wheels are 6,7. My suggestion is to leave the flat plywood part at home and only use the alu frame plus some small and light wheels. Drill holes in the box like you do with the BF tailer. I`ll look into weight for trailer frame only and size of same in a day or two. At the moment I am in my sons house and he has got the big Y trailer only (since I decided it was time for him to pull most of the weight
)