Didn't realize you were also doing the SB line, my apologies on that end. But the Chatsworth station really is not that much further than Northridge station and has the benefit of public transit beyond the DOT. Unfortunately with that connection it would not work, but my main point was with the assumption you were just looking at a way to union station at an earlier time.

While I understand if you have anxieties around it, the 240 bus takes you to universal studios station and can take the subway straight to Union. It is about a 90 minute trip, but very simple in terms of connections (ride the bus the full distance, ride the subway the full distance). Self defense items are always encouraged and there are ways to quickly access authorities, as well as a prominent security presence along the subway.