HMS Hermes (95) had IMO three flaws that I would like to address:
1) The huge destabilizing island and tripod mast
2) The inclusion of six 5.5" low angle guns (with FC directors on tripod mast)
3) The aft lift being exposed to the sea on three sides (was thus designed to enable aircraft to be moved from barge straight into hangar.
Here is Hermes at her launch.
You can see how high she was in the water before the island and other fittings were installed.
I suggest that reducing the island size, eliminating the tripod mast and anti-ship armament, along with enclosing the stern (if her keel and hull can take it) would make for a better ship. Hermes had wide elevators, and a good-sized rectangular hangar.
What other flaws would you like to address in the interwar period?
Perhaps squaring off the bows, removing the aft rounddown, adding crash barriers and outriggers?