We’ve decided to keep an editor setting to toggle the compilation manager on or off in 4.20. Removal of the old codepath has been postponed until 4.21.
In order to ensure that users are ready for removal we have renamed the .ini flag from bUseCompilationManager to bDisableCompilationManager. A warning will be logged if you are using the old flag. We’re doing this to ensure that users have a full release with the compilation manager before it is mandatory. If you are certain that the compilation manager does not meet your needs please start a thread here or on answerhub as soon as possible.
Cheers,