Originally Posted by glye

Yes, I'm also considering dual drive. I heard the SRAM one is being discontinued, but Sturmey Archer also has one, anyway. More weight/complexity than a 1x11 setup, but smaller steps between gears. Again, harder to fix if anything goes wrong on tour. Might as well choose a triple crankset, then I don't have to build a new wheel. The original 9-32t cassette won't fit on a dualdrive, I'd have to use a Shimano-compatible 11t minimum.

The original Deore Trekking setup looks like a long cage to me, though it doesn't say: htt¤ps://¤http://www.r-m.de¤/en-us/folding-bik.../#18B02_130411 (remove ¤ from url)
Yes, it's pretty low. I won't be riding offroad with it, but it's a risk.