@mic posting this for you to consider. This is for pistol grips, but basically the exact same two-sided machining setup you’re calling out for knife scales.
It looks like @wb9tpg is using a S03. I thought there was a post showing his two-sided machining, but can’t find it. His setup is doing exactly what you’re asking about - two-sided 3D machining. Even the earlier generation machines are (still) quite capable of machining aluminum and other materials with a high degree of accuracy.
The machines are capable, but you’re venturing into an area that is more operator dependent with tooling, work holding, jigs, software, etc. Lots of examples in the forum of people coming up with brilliant and innovative ways to use their machines!
If you’re interested in mainly aluminum, check out @Vince.Fab and @wmoy Material Mondays.