BF collector causes same model to be loaded up multiple times

This bug probably affects all released versions of new BF collector.
Symptom is that Maven with BF collector fails MavenITmng5669ReadPomsOnce both test methods. The IT verifies that POM XMLs are read only once with and without "consumer POM" feature enabled. Both IT methods fail (so failure is irrelevant of consumer POM feature being enabled). Error consistently happens on each subsequent IT invokcation, whether empty or prepopulated local repo.
Most probably cause: old DF was single threaded, while BF uses internally thread pool, that seemingly causes that same POM XML is loaded up multiple times as ModelBuilder is being asked multi threaded for different models by BF collector.

Reproduce: either run MavenITmng5669ReadPomsOnce but modify the IT to enable DF (if using Maven w/ resolver 1.x) or build Maven 4 w/ Resolver 2 (default is BF).