Would Germany build flak towers and prepare an Atlantic Wall?

Would Germany use the extra peace to build flak towers and stockpile for the Atlantic Wall?

Berlin flak towers are plausible, but the Atlantic Wall depends on a coastline and captured resources Germany does not yet possess.

The two projects have different starting conditions. Coastal fortifications in occupied territory cannot be assumed to have the same prewar priority. Captured French and Polish guns also form part of the historical resources that would be absent from this scenario.