By my calculation, 30 sec of animation at 30fps at 15-20min/frame = ~9 or so days of rendering. So yes, it is faster to correct in flame if it only takes 3 days. Of course the more you can get right in the render, the better, but I think it's unrealistic to expect there will be no requested changes to the render, or that there won't be some small tweaks to improve it in post. My two cents.
That's where I was trying to steer them. At least get the client's blue logo right. I am certain there will be tweaks. To output a cyan logo, and flat lighting is illogical. We know this client will be back, so I'm trying to convince people to get it right in Maya, and tweak in flame, rather then just output a flat & incorrect exr & re-light & CC each & every shot from scratch.