If you have machining ability there are all kinds of funnies one can make. Adapter flanges for instance. Find a rim with a larger number of spoke holes, say a 48H. Cut a ring out of sheet metal, sized to fit over hub flange and protrude enough to allow for a 2nd row of spoke holes outside the hub flange. Drill outer row in whatever configuration you need, then drill inner row to allow adapter flange to be screwed onto current hub. Remember that spoke holes are offset from one flange to the other.
Or use same concept to fit a motorcycle rim + spokes to a bicycle hub.
Or go for a 24H rim, they usually have to be fairly rigid anyhow. Redrill as 48H. Go for a paired spoke pattern, or you'll end up with one nipple trying to utilize the valve hole. It'll still be crowded, and final tensioning probably isn't much fun. But as far as I can see, it should be doable.
Might look for those nipples that can be turned with a kind of hex socket from the tire side of the rim instead of the regular kind.
Or my current personal favourite wheelbuild daydream, the double decker - which is probably a royal PITA to lace. Starting from a 36H hub in your case, and two 36H rims. Redrill hub as 72H. Use original set of spoke holes to lace to one rim, and bonus holes to the other. Just pretend you're using a rim with a whopping offset and the available calculators should be able to handle the setup just fine.
It'd be doable in radial lace, no doubt. But maybe 3X would lead to too much interference.