From the video, it sounds like they are local to the factory, near Toronto, and they said they actually visited to buy the bike, that makes things a lot easier, and Helix may prioritize local buyers. Yes, I was concerned from the start about mounting a rear rack, same issue as Brompton/Bike-Friday/Helix, a swinging rear triangle. I could envision how to mount one, just use forward rack stays down rubber/stainless wire clamps at seatstays, but would need to be removed to fold compactly. BF takes the rack off and folds (from what I've read, not durable, I could tell you why structurally). I wondered if that Helix rack folds automatically with the bike, but a close view on the video shows the rack verticals disconnect at the aft chainstay, rather quickly, I am guessing a ball socket, like the quick-disconnect steering linkage on some recumbents, and then it all folds against the bike. Not sure if that rack would support typical touring loads.

I have a Dahon Speed, haven't had to transport by air yet, but would anticipate pulling the rear rack and nesting it close on the frame, to make max allowable size. The rack itself is stout, rated for high weight, and fits well aft, placing the panniers behind the rear axle, for sufficient heel clearance. (This required super-XL length rack stays.) I prefer the Dahon because it has a much cleaner fold without greasiness, easily able to quickly fold for the train luggage rack, or ferry, for example, without rack removal. (What takes longer is removing and replacing the panniers (front and rear) and the trunk bag, I would need all for touring; trunk bag for tools and spares, front panniers for CPAP machine and batteries, the problem I have not yet worked out is how to CHARGE those batteries on the road, a front dyno hub is totally insufficient, so are solar panels.) The Helix, with single-side front fork, obviates a front rack and panniers, however the folding fork is brilliant in terms of a compact fold, close to that of a Bromption I think.

Other than the above, I would have preferred a Bike Friday, as MUCH better customer service (Dahon is useless), and already set up for touring, whereas it was quite a feat to set mine up for 21-85 gear inches, the frame isn't set up for it, I have significant adaptations. The BF price was also an obstacle, but they have made so many, they are now common on craigslist for half new price, but I would stay away from ones with an internal gear hub instead of double or triple crank, as IGHs are expensive maintenance and impossible to service in the field.

For soft soil, larger tires than 20" (406) should be better, but otherwise, 20" is no disadvantage on smooth roads, and still gives me a tall enough top gear with 50x11. I used a double crank, as 1X gearing with a low enough gear is out, due to the huge low cog causing the rear derailleur to be too close to the ground, that's the setup on a Burke 20, but I don't like it, and neither does an owner of one, he saw my setup and said he would have preferred it.