Changing login screen with Filevault 2 enabled

[mdonovan]

Has anyone successfully been able to enable FileVault2 on a 10.9.x Mac whilst keeping a custom login screen image in place?

We seem unable to do this, and our current theory is that Filevault detects this 'foreign' .png in the usual directory
(/System/Library/PrivateFrameworks/LoginUIKit.framework/Versions/A/Frameworks/LoginUICore.framework/Resources/), even if we rename the custom image with the name that OSX expects, and then refuses to enable encryption.

Any advice or experience would be appreciated!

[Look]

Could not find a way around this either, there is some kind of checking going on there I guess. Even if you the original files but alter them even very slightly it fails.