It’s hard for me to believe that using a CNC to mill a model for resin casting works better than 3D printing it and casting it. I’d expect that with 3D printing you can even print the spruce and risers.
On the first - i have an entirely ballscrew + linear rails driven FDM printer with closed loop servos and proper absolute encoders - I got bored and do lots of CNC retrofits/etc, so had lots of parts around. Think of it as insane version of the Pantheon HS30, if you didn't care at all about costs or practicality.
It can position, at speed (IE 300mm/s+), and repeat, the nozzle placement to within 0.0005 inches on all axes, easy.
But even with input shaping/etc, you will not get a better surface finish than CNC, and definitely not one good enough for casting.
Filaments are just too finicky, even with really really good hotends, sensors everywhere to monitor response and optimize, etc.
Now, i did this for giggles, and yeah, i never get misplaced layers, my parts are consistent, etc.
But 0.4mm is still a pretty big feature size, and that's the minimum if i don't want prints to take until the heat death of the sun.
So I could still machine the same thing on my metal mill and achieve castable surface finish, etc, in much less time and effort.