currently interface builder integration plugin generate wrong class name if class is annotated with @CustomClass without specifying the name. E.g.
package com.path;
@CustomClass
class Test extends UIView
will generate obj-c class Test instead of j_com_path_Test. last one is expected by runtime.
As result iOS will not be able to create subclass.

Also IB doesn't support generating outlets/IBInspectable for Struct classes such as CGRect/CGSize/CGPoint/NSRange