https://www.cyclemonkey.com/schlumpf-drive-haberstock

The problem with 1x is the range is more of an either/or situation. You picks what you gets. For obvious reasons the 500+% range of a Rolhoff is great, but the cost is prohibitive & the shifter situation is limited. Of course there is Gebla, at further significant expense if you are so inclined.

The Schlumpf drive at ~$800 gets you 1x simplicity with the gear range of a triple. Combined with Gevenalle shifters, you can have most any number of speeds you want. They index up to 12 speed, but can be run in friction mode for any cassette you desire.

How does 700% range sound for around $1100 all in? Good?
Good.

As long as we're buying high torque drivetrains for heavy loads, don't underestimate the wonderfulness of long lasting steel freehubs or freehubs with anti-bite guards. Aluminum freehubs get cassette bite far too easily & don't live very long in uses like this. A touring bike sees a lot more hours in a lot more remote regions than a mountain bike. There is no sense wasting time with an aluminum freehub with skinny individual cogs like found on 11/12 speed cassettes. A steel or titanium 10 speed freehub would do you right.