To be able to get rid of this it will need to switch the handler setting to one that is a list of class names instead of extension names, hence use autoloader instead of the 3.x way of loading handlers.
Basically similar to how we changed lots of handlers in 4.1 to use autoload, feel free to create a pull request for it but remember: Do not re use same setting name, extensions should be able to support old and new eZ Publish versions. And remember to add bc note about it.
