The `ParallelRefProcBalancingEnabled` flag controls whether the internal queues used in reference processing should be balanced before being processed in a multi-threaded context. It is enabled by default, and there is little reason to disable it in modern usage.

Maintaining this flag adds unnecessary complexity to the reference processing logic. To simplify the codebase, we propose to remove (deprecate then obsolete) this flag.

This flag is exclusively utilized by the Parallel/G1 GC.