This is the kit I bought: https://www.aliexpress.com/item/microsquirt-II-based-EFI-motorcycle-Motorbike-Motocross-ATV-scooter-small-engine-Electronic-Fuel-Injection-kit/32786077851.html?spm=a2g0n.description.0.0.5b1bb3c5KNPpBp
I am using TPS/RPM (Alpha-n) for fuel ratios. Open loop. I only operate a WOT so don't need to be too fancy. What I'm doing probably won't be too useful to a normal moped. I think that adding EFI wouldn't be worth it for most people. I'm doing it for a few reasons: I want to try it, I want that last few percent of power, I have the background in embedded control systems and I have a lot of equipment available to me.