I'm using the NetBeans internal profiler to optimize BPEL Mapper loading.
It turned out the schema's targetNamespace attribute is requested very frequently.
It's caching should help to increase performance for about 10-20%.
Fixed in trunk:
There is a fix + JUnit test
Integrated into 'main-golden', will be available in build *200908041401* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
Log: #169435 - The targetNamespace attribute has to be cached for the sake of performance optimization
Verified with JUnit tests + verifying different BPEL projects
The fix has been ported into the release67_fixes repository.
Verified by Michael Nazarov.