DBA Day1 CPT or UC 2nd Masters

My wife has an STEM MBA from one of the UCs, but is yet to get a job after one year opt. She can’t apply for STEM extension because no employer at the moment

She has gotten admission for another master degree from the University (No funding) or GSR. I’m also considering she enroll for DBA so she can still keep applying for full time job and she can get OPT and STEM OPT after completing it unlike the second with any work benefits.

Any advice, second masters or DBA? And how long after OPT end date can she activate these moves?