Question regarding dynamic_library_path

Why does postgres maintain a loader logic of its own? I can understand that
the dynamic_library_path is necessary in order to configure everything in
one single place. But why not just merge it with the LD_LIBRARY_PATH (or
PATH on Windows) and then let dlopen do the rest using a stripped filename?

The reason I ask is because I run into problems as soon as I have a module
that in turn depends on other shared libraries. It doesn't help much that
they are reachable through the dynamic_library_path since that path never is
made known to the OS loader mechanisms.

I'll be happty to submit some code to do the actual path merging (i.e
omitting duplicates etc.).

Kind regards,

Thomas Hallgren