Yes, that seems to be the way to go.
Have you had models cast this way? And do you have any examples of how that turned out?
I had very few miniatures cast, although I have gone this route for components for terrain, but I was able to cast the resin masters myself for those. Tbh the last mini which faced this I ended up just getting cast in resin as it saved the money and time in getting the metal casting mould done. You might try this if it's a short run, resin casting moulds wear out much quicker than the metal equivalent though, so if it's a long run metal may prove more economical. The results were excellent.