I expect there will be a lot of things I have to change and fix. I've never balanced a 3 stage map before - I thought perhaps doing it stage by stage would be optimal. I was hoping those with more experience than myself would chime in.
What's your experience Grim Tuesday?
I would actually suggest doing it in a normal series... but have all of the cp_loot_a# maps only have the final round. Once you're pretty close to finished with round 3, then move on to the cp_loot_b# maps, which will have both round 2 and 3 connected together. That way, the final stage will still get some playtesting, but round 2 will get the majority of exposure. Simply repeat the process again for the cp_loot_c# maps.
I found the benefits of this system, even when just used internally, to be enormous. Everyone, most importantly server owners, will know which map is furthest along. Furthermore, for the first two thirds, people will just see it as an "alpha" or a "beta" map, and won't get confused by the naming process.
Best of all, this system allows you to still have people examining the details of the later rounds while you're still playtesting the first for balance.
The only downside to this is that you'll have additional time where the first things people see are dev textures, which slowly become more and more detailed as rounds progress, which is slightly counter intuitive. Additionally, this requires you to work on the points in a reverse order. Other than those two problems, this system allows you to work on each round independently without confusing the public.