Is there a reusable material, hard wax, that can be utilized for prototyping objects? If there is an error of any description you simply gather up the pieces, melt and recast, change machine settings and start again.
Yup. Machinable Wax.
If you have a degassing chamber, you’ll get a good block on the remelt. Vacuum it if possible. Ferris green works well.
edit* Use an upcut bit.