It seems at least some of us are out riding our bikes. I have been
anyway. It's been my regular ride to work, 70 miles a week.

Technically, the only things to report are that after a lot of thought
trying to get the chain run to work nicely with a tube on the top run
and the single pulley on the bottom run, both as supplied by Dom, I
concluded that only a tube on the top run was not the most efficient
arrangement. So I got an Optima pulley, which comes with a neat
bracket for supporting chain tubes either side of the pulley on the
top run, and a single long tube on the bottom run. A bit pricey, but
much neater than the original parts and it feels more efficient.
There's also less of the chain rattling on the handlebars (mine's
USS). (Optima's online shop is off line at the moment, or I'd post a
link).

Oh yes, and I made a pannier rack to carry a second pair of panniers
beneath the seat. Standard ones won't fit because of the USS linkage,
so mine's built to fit around that. Works well and allows me to carry
a pair of "front" panniers under there. Their side pockets are
accessible while moving.

I'm curious to hear how a Bentech with equal sized wheels would work
out. Are you thinking of two 26" wheels, or two 20"? I ask because
Mrs Uncle Phil would like to try one, but she's too little to get her
feet on the ground on my standard SWB Bentech. I wondered whether we
could build one on two 20" wheels, which would make the seat sit a bit
lower. Unless the geometry of the rest of the frame were altered ,
though, it'd be a bit odd to ride I would think.