Looking at the rendering docs, it mentions Godot using Voxel Cone Tracing for a GI solution. I'm wondering if it's possible to turn that kind of thing off for a project. Bake all lighting, and have not GI computation even if I move lights around.
You can use baked lightmaps instead of GIProbe.
By default, BakedLightmap will bake only indirect lighting, but you can set it to bake all lighting (in this case, don't forget to hide all light nodes before running the project).