I understand that the provisional unlawful presence
waiver process will significantly reduce the time that U.S. citizens
are separated from their immediate relatives. Do you know for how long one would have to leave the U.S under this new process?
Information about the process is being still being released, but the idea behind the stateside waiver is for people to be able to overcome the "unlawful presence bar" at the time of their consular interview. If an immigration attorney has reviewed a case and determined that this waiver would resolve all issues preventing the issuance of a visa for someone, and the waiver is approved, then that person should only have to leave for as long as it takes to complete the consular visa process (the requirements of which may vary by consulate).