Should my wife transfer to MOHELA?

My wife is in year 1 of medical residency (at a qualifying employer) and just had her loans consolidated in November. Her Income Based Repayment plan application is still being processed by Aidvantage. As I understand, she would have to apply for PSLF which would mean her servicer would change to MOHELA.

Is there any benefit to applying for PSLF early rather than after she’s completed the 120 qualified payments?

Thank you!