For the bike touring enthusiasts among us: I got an interesting update from Peter concerning accessories. Once production stabilizes, they are going to turn to the promised set of accessories, aiming at the third quarter.
As to trailer support: since the helix features its own unique rear hub endings that will not take a trailer, they are going to offer some universal adapter that will sit somewhere near the hub and take hitch balls and other common trailer attachment.
The helix is confirmed to fit into the radical design chubby 4 trailer, which is good news for me. In the past I traveled abroad with Brompton, using this trailer as bicycle case for transport. Airlines normally allow 23kg per suitcase. With the trailer weighing 6kg and the my fully-accessoried Brompton weighing 13.5kg, that leaves a meagre 3.5kg to squeeze some equipment in. With a fully-accessoried helix, I expect a gain of 2kg, which, for bike-touring, is significant!