Main purpose for having wsrep sst donor rejects queries option

What is the main purpose for having wsrep_sst_donor_rejects_queries option?
When we switch this option to ON (and disable any lock options), our sst through xtrabackup crashes on query “FLUSH BINARY LOGS”
So, as i correctly understood, we can not use this option with xtrabackup sst method.
Am i wrong?

@asker That sounds like a bug. Please report it with a repeatable test case at