In A&A Revised, Baltic Carriers were popular among some people. For Revised, I generally didn’t like it as the Axis, loved to play against it as the Allies, but many people will disagree on whether or not it is a good idea. You’ll find probably dozens of threads on Baltic builds in the Revised section. I haven’t played much 1942 Edition so can’t say for sure good or bad, but my gut says no. A Baltic carrier somewhat separates the Allies from helping the USSR - quite an accomplishment. But in doing so, the USSR doesn’t need immediate help from their Allies and may even be able to advance to Ukraine.
How would the Allies go about killing it? The generic counter of Baltic navies from Revised is to merge the British and American navies to take Norway between rounds 2 and 3 depending on game conditions. Before making their move on Norway, both of the Allies will probably land Algeria once or twice. While doing this, they want to prevent a German move to the English Channel, usually easy to do. Once the Allies move up to z6, all they need to be able to do is defend the North Sea against the combined air and naval attack. The Allies will funnel units into Norway to trade Karelia for the Soviets. When possible, take Norway with enough that Germany can’t trade it back. The British can typically afford to build 1-2 naval/air units a turn while keeping a flow into Northern Europe. Keep constant tabs on your odds at attacking the Baltic, if you see an opportunity to trade boats for German planes, go for it - just don’t leave your transports out to dry. Most likely, Germany will reach a point where they have to choose between saving Europe and the Baltic and they will undoubtedly choose Europe. They simply can’t keep up at sea.