One niggle about the single wall tunnels. I always used to get a fair amount of condensation along the walls, a little bit up from the floor. This was with awnings over the ends, but otherwise open, except for the netting.
That's what drove me to other designs with the entry located on the longer side of the tent. Perfection would have been if Henry had figured out a way to to have netting walls at both the front and back of the Moment, like the Scarp, but without the four corners. There can still be some condensation overhead with this approach, but on both sides of you, from head to foot, there is the netting, which for me, makes the inevitable condensation on a single wall much more tolerable.
Although there have been some attempts, the tunnels don't seem to lend themselves to netting along the length of the tent, on both sides. Unless the center of the tunnel is much larger than the ends, as in the tents mentioned above, which kind of grates against your concern about the pole length. The beefier carbon poles, like the Easton FX, can arc 7-8 feet, though, with a pole 10-11.5 feet long. Not sure that this longer pole length is that big a deal when it is only one pole to be threaded through one sleeve, and guyed if needed.
We see pole sleeves less and less now in the US, and more and more clips. They seem to think we are too lazy or stupid to thread sleeves, so must have the clips, despite the downsides. And not just for 'folk festival' tents. Ditto on the 'freestanding' domes. The smaller companies, not so wedded to these developments, or MYOG, seem to provide the only alternatives.