Just my thoughts exactly.

For a mass produced carb this would be bad but as a upgrade to a previous engine (attach bigger carb) it would make tuning so much easier to joe average. I guess having fixed jets makes sharing jetting easy on forums but at the end of the day every engine is different, compression ratio, cam type, inlet flow, exhaust restriction - so even having fixed jets and telling people your jetting doesnt really help.

Me having access to a full machine shop (and a lathe and mill at home) this looks like a interesting project - hell I'd even make the carb from scratch.

Locking the screw can be done by low viscosity loctite that wicks or better yet, a small double nut to lock the screw.

Those Walbro type carbs spring to mind when thinking of all this but they are far too small with their 1/2" venturis.