https://bugs.winehq.org/show_bug.cgi?id=44229
--- Comment #2 from Zebediah Figura z.figura12@gmail.com --- (In reply to Alexandre Julliard from comment #1)
Avoiding duplication is one reason, the other is that we don't want to export a whole bunch of 16-bit functionality from user32.
How should custom templates be implemented, while avoiding both of these things?