What sort of work do you wish to do?
How do you wish to approach it?
One way to extend Carbide Create is to use other programs as a front-end to make files for it:
vice
and
https://www.blockscad3d.com/community/projects/1318915
Fusion 360 and Vectric Vcarve are two very different programs — the former is for 3D mechanical modeling, while the latter is a 2D drawing program which has the ability to make 2.5D toolpaths (much like Carbide Create), Vectric’s Aspire adds 3D modeling (as does Carbide Create Pro).
I use BlockSCAD/OpenSCAD a lot, and have been looking into RapCAD, but I’m lazy and inclined towards programmatic approaches.
Many folks use Inkscape or Serif’s Affinity Designer as a front-end for Carbide Create — my suggestion would be to start w/ one of those and see if it addresses the lacunae.