What I would prefer is do my designs in Schematic, then run the diagram in Simulator. If there is no SPICE model for a particular part, it should not be listed in the parts, and having found one online, there should be a way to add it to the global list of SPICE models.
The parts not included in KiCAD 9.0.0 are surprising. It’s missing 2N3904, 2N3906, and 2N2222. I have found what purport to be SPICE models which describe these parts, but have found no way to include them in the KiCAD database.
As I go along, it appears the answers to these and other questions are pretty obvious…to those already thoroughly familiar with the system. It shouldn’t be this difficult.
SPICE models do not operate like symbols or footprints (with a table of libraries that KiCad can scan), more like the 3D models where the footprint’s model field points directly to a file on your computer.
KiCad only includes a handful of generic models/settings for symbols in the Simulation_SPICE. Most models you’ll find online have licenses that prevent re-distribution by KiCad, so it is on users to find appropriate models and associate them with symbols as needed in their designs.
If any of the models used by Schematic can contain all the information needed for SPICE, then they all can. I’ll grant the copyright thing is a problem, but even so, users should be able to use standardized forms to enter the appropriate data themselves, then share their home-written models with others.
KiCAD is the base I want to stay with because I’m already using it.