I’ve been meaning to share this mod for a while now. For the last four months I’ve been riding this configuration of UW almost exclusively, almost everyday, for 1-2 hours:
I use these type of pedal extenders and can arbitrarily set how far from the wheel I want the pedals. For me the sweet spot is 2 of these extenders which totals an extra 55mm away from the wheel.
Beyond allowing an arbitrary distance from the wheel, there is another huge advantage to using these vs just taking a unicycle wheel off (“cranky” ultimate wheel). With a cranky UW, if your feet are not straight on the pedal, or are too close to the inside (either from imperfect mount or shoe sliding on the pedal) then it can happen that as you come down past 3:00 the crank will try to lift your foot off the pedal (since you are partially over the crank), or as you sweep back past 6:00 the crank will hit into your ankle bone.
With an “extended” UW, this does not and cannot happen. The extension is always in the same plane as the pedal, it is always simply an extension of the pedal plane albeit narrower. I can ride with my feet at 45 degrees, or with my feet almost entirely on the extension and off the pedal, there’s no issue. Rides like a dream, to me. 
One reason I prefer this over a disc type UW is that I’ve fallen in love with this (albeit brief for me) feeling of riding while the tire is not touching my leg at all. For me in this extender configuration, for every rev, I get more time where the tire is not touching either leg. I’m still only rarely getting full revs where it doesn’t touch at all, (where I’m simultaneously panicked and excited) but at least that. I never get those with a pure disc UW. With this setup you have much more play before the tire reaches your leg, lots more freedom to handle riding on rough surfaces without the wheel catching your leg. There is something really cool about the feeling of riding this thing and the only point of contact is your feet. It’s like you’re walking on air.