Unity, connecting unlit shader output to compute shader?

I’m hoping to learn what my options are for sharing the outputs of simple unlit shaders with compute shaders that will operate on the data.

Is my only course of action to use a render texture with the unlit shader, and Graphics.Blit to render the shader to a texture2D that can be set on the Compute Shader? I was hoping something like a ComputeBuffer or GraphicsBuffer might be made accessible and writable in the unlit shader and then could just be used in the Compute shader also.