Custom Settings (settings struct) in Coldbox.cfc: Cannot make use of (global) UDFs imported via UDFLibraryFile before ?

I just wanted to make use of the Coldbox Custom Settings feature: The
'settings' struct in the Coldbox.cfc; in the 'coldbox' struct of the
Coldbox.cfc, I import all (global) UDFs via the 'UDFLibraryFile'
directive; the 'coldbox' struct comes before the 'settings' struct.

In the 'settings' struct, I want to assign imported UDFs - for
instance as Callback Handlers - to setting variables.

BUT: I receive the error message 'variable [IMPORTEDUDF] doesn't
exist' !

Is this correct behaviour ? If yes: Whereelse shall (global) UDFs be
assigned to (setting) variables ?

I had just moved those Callback Handler assignments from an
onApplicationStart Handler to the Coldbox.cfc settings struct ...