Is it possible to render without loading a vertex or fragment shader in bgfx? Maybe this would effectively just be a default shader. The very first example to have any geometry also has 1 or 2 lines of code simple shaders that do little more than what OpenGL would do by default (I think), but it would be nice if it were possible to have an even more simple starting example that also has a 3D cube or triangle getting displayed.
No, shaders are mandatory, both in contemporary OpenGL and in serious libraries like BGFX.