I made some changes to the VAB source code and figured I need to change all PublicKeyToken attributes that refer to the VAB assemblies to null and change the EnterpriseLibraryConfigurationSet to "EntLib3Src" to get it to work, which it does when I do that.
Now when I sign the VAB assemblies with my own key (which is recommended in the VAB help) the configuration gui says that it can't identify the the type "ValidationSettings", probably since the gui doesnt know the public key of the assemblies. So I changed
all the PublicKeyToken attributes to our public key - but that didnt help.
Do I need to add my own ConfigurationSet somewhere or do I need to install the assemblies into the GAC? It's not really much of a problem for now, but I still would like to know the solution.