Given the fact that all escort carriers were in fact reconstructed merchant ships, i'd love to see the ability to transform your transports to cvls! 
I thought convoy escorts are DD -1 ?
All of the pre 1941 CVLs are really CVEs, and in 41 they separate (though still both in the same 'type') into CVL's (aka mini-carriers without the need for CAGs) and CVEs (more or less only good for spotting support, so important for SAGs)Light Carriers (CVL) and Escort Carriers (CVE) were not the same sort of ships. Escort Carriers, whether converted or purpose built were slow, small, and cheap carriers designed either to protect convoys or ferry aircraft to the frontlines in the pacific. They were not supposed to find themselves engaged in actual battles.
Light Carriers in contrast were generally purpose build, or converted from partially constructed warships. They were simply scaled down Fleet Carriers, designed to alllow for faster , and cheaper construction of individual units which could if need be take place in commercial shipyards. They were intended to fulfil the same roles as the Fleet Carriers, just on a smaller scale.
As I understand it, currently in game CVEs are abstracted as part of convoy escorts, whilst CVLs are the ships we can build and deploy with fleets.
All of the pre 1941 CVLs are really CVEs, and in 41 they separate (though still both in the same 'type') into CVL's (aka mini-carriers without the need for CAGs) and CVEs (more or less only good for spotting support, so important for SAGs)