List Module in Backend is very slow due to Extbase's Typoscript parsing
While profiling the Backend with XHProf I found that each click on the list module triggers a complete TypoScript parsing.
This is done in sysext\extbase\Classes\Configuration\BackendConfigurationManager.php->getTypoScriptSetup()
this method actually has an internal cache for typoscript but this cache only hits when getTypoScriptSetup() is called 2 or more times during the same request. If I hit the list module with the same pageID again a new request is triggered and the complete TypoScript is parsed again.
Making this cache persistent (e.g. by putting it in the Caching Framework) would be a great speed improvement for the Backend.