I've been struggling a lot with artifacts from the Indirect Volume lighting. I experimented with the size of the IrradianceVolume (points closer to the walls, further away), the resolution 10x10x5, 40x40x10..., and the position of my lights in the scene. Most experiments end up looking like this:
Given the struggle and how long it renders, wouldn't it be possible to bake the lighting from cycles, and then use that in an Evee when rendering the final animation?
Yes, that can work, it's a valid option, if you're referring to baking the light information into a texture. Though it's a step into complicating things more than it needs to if you ask me. Baking the Irradiance Volume is a pain yes, there's gotchas here and there. You can watch the Lighting Course by JL if you haven't already to get a hang of lighting in Eevee:
https://cgcookie.com/courses/fundamentals-of-digital-lighting-in-blender
