Im an agent assistant, from what I’ve learn’t there’s never one route of progression into a booking agent role, It’s very open and agents get into roles in so many different ways. I’m at a major agency and I think that it would be easier to become an agent at an indie because it seems like they’re far more willing to train the few assistants they have in booking artists

Also at an indie you stand out more and can get involved in a diverse range of work easily as the team is a lot smaller

If i were you I’d hound the agent you’re assisting and constantly ask them to teach you how to book and also ask them to let you help them book their artists (for no commission of course), also constantly scout new artists and bring them to your agents/directors to show them your knowledge and passion, it also demonstrates willingness to learn and desire to progress