momoman,
Congrats on the mods. Just be aware, 1-1/8" tires, and most especially on deep section rims and 20" diameter with tremendous hoop stiffness and strength, mean there is very little radial elasticity in that system. Just to prevent pinch-flats on an unexpected pothole, those tires will need to be aired-up. A really big smash may still go past the tires and flatten the rim near the bead, though probably not affect the rim as a whole. There are cases with 700c bikes with deep section aeros where the front wheel ran into something, and the whole fork bent before the wheel did.
What I would like to find, I don't think exists, is 20"/406 rims, double-wall, but with "double-rivets/eyelets", that have the spoke nipple pull on both inner and outer wall, that improves fatigue strength tremendously, no radial cracks at the spoke holes over time. This is a common design on proven-for-decades touring rims. But it does add weight, and exactly where you don't want, at the wheel rim, so increases rotational inertia. If not that, a double wall rim with the inner wall extra-thick at the nipple, and perhaps me also adding small steel washers under the nipples to spread loads out more. What's my name?
On my Cannondale racer, after wearing out 2 sets of wheels over 6 years (at over 7,000 miles a year, would have been more except for snowy winters) due to a crack at the spoke hole, and the cost of replacements, I then bought a good set of double-socketed rims (great winter price on Nashbar!) and fit 32mm tires (I had to just dust the aft part of the front derailleur with a file for the tires to clear), and that improved both ride and durability. I still have that bike and wheels, just haven't ridden it in 18 years, as I need a townie and panniers now.