On a similar note (my curiosity often outruns my threshold of comprehension and I get smacked down for it)..
there is a thread here on diaphragm/pumper carbs. Like 30dillon, I asked myself... "I've been tuning weedwhakers and motorcycles for years... why did it never occur to me to ask why the diaphragm carb is not suited to a moped/motorcycle."
It's a very interesting dive into the web. So it's not so novel after all? Found a few relatively exhaustive threads on motocross forums. After a few hours it seemed to come down to a bit of consensus.
Best for tiny engines like weedwhackers where low and mid power and response are not critical... ie, wide open all the time! Also these tiny engines are not optimized for fuel efficiency, but reliability and low cost parts. In most cases, a swap from float to diaphragm carb will penalize fuel efficiency regardless of any performance gains you might painstakingly tune into it.
Seemed like the majority of experimenters with motorcycle applications ended up after an often long winding path, just slapping the ol' reliable float carb back on and calling it good. (edited)