There are a few recommended open source tools for designing lattice structure with Artisan. Please be aware of the licenses of these software as they may be charge for commercial applications.
Salome Platform: https://www.salome-platform.org/
This is a general CAD platform that integrates many useful features for CAD modelling, FEA/CFD mesh generation etc.. Artisan requires meshing inputs to create mesh lattice and conformal lattice. User may install Salome to create their own mesh.
The geometric model of lattice infill could be easily reach to a level of over 1 GB. Paraview loads, manipulates and browsers the large models with the minimum lagging experiences.
A popular open source mesher for FEA/CFD modelling community. It charges license fees for commercial application. It is lightweight and easy to use.