An angled deck was not chiefly a counterweight

Did the angled flight deck make carrier design easier by counterbalancing the island?

Only marginally; the more important high-weight problem was the hangar and aviation infrastructure, not the island alone.

The answer allows that an angled deck can help in some respects, but rejects the idea that it was primarily a counterweight to the island. A properly designed carrier can account for the island's mass within the overall balance calculation. The larger naval-architecture challenge is the substantial weight placed high in the ship by hangars and aviation infrastructure. This keeps the technical discussion grounded in the whole carrier rather than its silhouette.