Split, trim brushes to add articulation points to sculpted figures?

Yes and no.
No, you can’t do it like in zBrush.
Yes, you can do it differently in Nomad:

Nomad has no IMM Brush like zBrush.
But it has an insert tool.
You can create or import the objects needed and use the insert tool to place them.
Use this trick to place them directly on surface.

Second, Nomad has no Live Booleans. Every boolean operation is destructive and it uses voxel remeshing. Voxel remeshing means loss of detail or very high density mesh.
But as this is last process before printing, you can decimate after.