Ask how many units they manage and how much experience they have.

I would need to learn more about my options though as my experience is limited to podcasts and a few articles on that subject. 

I've only had one listing transaction from my BP leads.Most are complete noobs or have limited REI experience with a rental or two.

They claim to market on dozens of online channels, and they seem to know the right amenities to feature, have great design, services, experiences etc.

My piece of advice would be to make sure you have a great agent in your corner to help you assess the market, make informed decisions, etc. having a good agent can be day & nights difference when it comes to your experience.

Being young will present challenges in a field where experience is highly valued not just with lenders.

In my experience, most agents are lazy and don't put in a lot of effort (maybe they just do RE part time). 

Quote from @Jay Fayz: Hello everyone,I've recently been exploring real estate as a potential career path and I'm looking for advice on the best entry-level job to gain experience and knowledge.

Sounds like for now the idea of eventually selling the branded account is a no-go, but there still remains pros/cons on each option and I'd love to hear what others have considered or their experience in adding more STRs/boutique hotel type properties to their portfolios.

A financial advisor with real estate experience can help you plan effectively.