Update on my EZ-1 20" rear geared build: I'd shared earlier that my rear wheel with freewheel was not well-centered in the frame. I'd hoped to address that by disassembly & reassembly of my DNP 7-speed freewheel, such that leaving out the biggest ring & spacer would result in a thinner but useful 6-speed freewheel. I had it apart & reassembled as a 6-speed but the design wouldn't allow me to fully snug the gears tight using the lockring, due to limited hub thread depth.
I've searched pretty exhaustively for a 6-speed freewheel with an 11T small gear. IT DOES NOT CURRENTLY EXIST to my knowledge. I contacted DNP about my wish for one, they acknowledged my request, said they'd get back to me, we'll see.
Plan-B, I used a threaded rod, nuts & washers to stretch the dropout width by 10 mm so that additional washers needed to better center the wheel would fit. The wheel is still not perfectly centered, but way better. It remains to be seen if the center-pull brakes can be adjusted to accomodate the wheel location, or if I will still need to "dish" the wheel some, or not. More as time permits...