Turning an Illustrious-class carrier into an amphibious aviation ship

How could four undamaged Illustrious-class carriers with modern radar and anti-aircraft guns be used?

They could take carrier-support or LHD roles after deck, lift and machinery changes, with useful F-35B capacity but a smaller air group than a larger carrier.

Four undamaged Illustrious-class carriers appear in the hypothetical already fitted with modern radar and anti-aircraft guns. Their flight decks would still need work, but they could support carriers or take some LHD roles. An equivalent modern radar fit is compared with the Type 45 suite, alongside multiple 76 mm mounts. Gas-turbine conversion and modified lifts are suggested for F-35B use. They would provide useful additional aviation capacity without carrying the same full air group as a larger carrier.