On MIM parts:
At least for the degree they are used today,its a relatively new technology...sort of.Ball bearings and gears have been "sintered" for a long time.
The process has been adapted to injection molding.
For nearly all manufacturing technologies there is a learning curve.The designers accustomed to traditional manufacturing process have found trouble creating clones of forged/machined parts in MIM parts.It does not necessarily work.For example,molded parts require uniform wall sections. A very heavy wall section (like a traditional hammer) creates problems.
The parts adapted to MIM may not have the real estate for a traditional DA Revolver design.
The plan of starting with a clean sheet of paper and creating a new design to capitalize on modern manufacturing methods is a good one.
Stoner did that.Glock did that. So did Eli Whitney.And Bill Ruger.
By whatever forming technology,powdered metal parts are not inherently inferior gun parts. They just have different characteristics. That may frustrate a pistolsmith. Fair enough.
Consider a chef knife edge.It requires certain characteristics.
These days,the chef knife "super steels" include powdered metal, R-2 and SG-2 among them.
https://www.chefknivestogo.com/sg2steel.html