Best way to preload shader and/or other assets at level start

Finding a number of spikes/hitches in game thread activity from profiling and it looks like this is due to loading of shaders tied to mainly particle effects but it’s possible there may be other objects involved as investigate further. I’m seeing behaviour very similar to what’s described in this thread. Preloading of the shaders and/or assets using those shaders seems to be a good way to try fixing these hitches but what I’m not clear is the best way to load all objects in the scene for preloading. I can seemingly dump an instance of every object in the level though I’m wondering if there might be a way to load just the associated shaders and/or lessen the load of trying to load an instance of every object we would use just to get the shader cache prepared.