I just built up a new coker rim to a Nimbus 48h hub. Before I built it I drilled 7/8" holes on the outer wall. It looks great and is supper stiff. Unfortunately I don’t have a scale here to see how much weight it lost but I am pretty sure I now have a sub 1000g rim.
I recant what I said earlier about my airfoil being not really stiff, I later realized that it was just my Nimbus frame bending while riding. My new wheel stuck in a KH frame should be much stiffer.
I am going to ride it like this for a while but am thinking of re-lacing with 24 spokes some time next year to see how it feels and how well it holds up.
Sounds awesome Saskatchewanian, could you post some pictures of the rim? 
adding more spokes can increase rotational stiffness, that is, power put into the hub will be more efficiently transfered to the rim. This can easily account for the extra weight. Aluminum is stiffer than steel which will add to the stiffness of the system.
I will also rehash the rotational inertia argument, saving weight at the rim while increasing the total weight will actually make a wheel feel lighter.
I race mountain bikes on my bike I have wheels that have the spoke nipples at the hub instead of the rim. The wheels are by no means considered light but when people with race wheels that can be half a pound lighter than mine, ride my bike, feel little to no difference.
Unicycle weight is most important when hopping, I don’t know a lot of people that do trials on the 36". I am by no means saying that weight is not important in other aspects, just less noticeable.
I sure the guys are Coker tried the new rim with different spoke numbers and cross patterns and determined that in some extreme cases the rim would not hold up without the extra spokes.
mmm maybe not sub 1000g as I found my original pre-drill weigh in and it was more than I remembered.
Pre drill it was 1175g so about average for a 36er rim. I only drilled the outer skin so I probably only brought it down to 1100g.
The hub on the other hand was 765g. Pretty hefty.
I didn’t take any pics of the finished product but this is it during the drilling process.
