Having spent a million dollars making gears, my ultimate conclusion is it’s the sort of thing you machine from brass gear stock unless you want to spend a million dollars.
So you can decide on a module/PA, buy a few diameters then cut off the required face width you need and machine the bore as needed.
Breaking tools and getting G-code just right seem like the perpetual headaches of modern machinists. Other than occasionally being bitten by a bitchy blade-like chip begging to fillet your grizzled knuckles one last time before banishment from the bench to the backyard becycling bile of betal bits.
If electricity were cheap (or the electric meter rewindable), would multiple beam concurrent FDM be a consideration if the materials and metallurgical characteristics allowed it? I think at some point, it's easier to print complex shapes additively than machine them subtractively, and that needs to be part of structured cost decision-analysis for manufacturing.
Problems.
No problems. After they are fixed by the meat confusor.
They are solved.
Your tool in a vise.