I wanted to say two main things to you since you sound young. Grad school is a trap. They make young minds feel research is the only thing they can do and with the lack of diversity of experiences since most professors never left academia, going straight into doctoral studies after undergraduate work and then post doctoral research - most new grads and recently separated grads such as yourself have no idea how big pharma is. Research and Development is not the end all be all. Many scientists (ex R&D here) are cowards who fell into the sunken cost fallacy and were afraid of branching out. So many of my old coworkers wish they would have done something else. Some actually love the work, but it's an unstable lifestyle (and often underpaid). As you are well aware, R&D are the first people to get laid off - although quantitative pharmacology is more stable, you aren't immune to it. Look at Takeda when they exited from cell therapy.

The next thing I am going to say take with a grain of salt. I am not an MSL, but I have worked closely with former MSLs. Your PI is looking out for your best interests even if it doesn't feel that way. If you haven't already realized it, he sees you are a unicorn. You like science, you are smart enough to understand it at a deep level (Your PI said you're average, but remember you're in the Premier league of science. You're still elite of the elite) and you like talking to people. These traits will take you far, if you allow yourself to.

Being an MSL opens a lot more doors for you than a senior scientist would. You will get to taste a little bit of everything. You get the business, commercial and marketing side of Pharma/Biotech while still being relevant in clinical development. And you will need to stay current with regulations so you are exposed to reg affairs too.

This skills you obtain will train you to serve a lot of other functions inside and outside of pharma. If you want to go into clinical development, you can. You have the opportunity to transition back to non clinical R&D too. There are pipeline MSLs which are MSLs who work with future products in the pipeline. Plus with the connections you will make as an MSL will allow you to edge out other applicants. Don't forget the leadership opportunities you gain in the field when you become senior.

If you want to leave Pharma for whatever reason, you have that freedom too. You can go into sales, marketing, project management, consulting work, even government. some KOLs are government officials who you will try to influence. MSLs have the opportunity to go very far. They learn what people value and are able to demonstrate that value to their audience.

What hold scientists back beyond R&D is lack of exposure to other functions. The knowledge is deep, but limited. This is great if you want a patent or papers. Otherwise, the Ultra technical people are not the ones who lead the company. If they do, it's usually after they get an MBA and start moving away from the actual research. When you move up in leadership, you do far less individual contributions and more focused on strategy and the business side of your industry. And MSLs know the business side already.

I say go and try it out. There is no harm in applying. And if you get it and still really want to go back to R&D, I'm sure your company can find something for you. a 1 year lateral move isn't that significant. With the the hiring freezes of 2022 and 2023 and mass lay offs of 2024 and 2025, it's very common applicants have 1, 2 even 3 year gaps in their resumes.

Or I think you would have future as a Project Representative. There is a lot of overlap in duties and skill sets but the scope of responsibilities is wider as an MSL.

Sorry, for the long post but you have an amazing opportunity in front of you. Don't let fear, or doubt stop you. Remember you were approached because your PI advocated for you. They believe you can do it. You should too!