The Hawkins at 10,000 tons are the only real option here - I think 10,000 ton conversion is the lower limit and Casablancas aside 10,000 ton is pretty much it for a purpose built CVE/CVL
One of my darlings which is often murdered which I might one day write
Another option is to partially remove armament and turn some of the earlier Crusiers into 'Sealane control Cruisers' with a Catapult, crane and seaplane hangar for 2-4 aircraft (such as a Swordfish Amphib)
And to be fair to those Casablanca class they could manage large aircraft as well if using a deck park!
Yes I was trying to be funny
I like that solitary biplane. It's like "yeah, we got room for one more!" That photo reminds me of moving in and out of the dorms between semesters at college.