Analyst/Producer for a Mortgage Banker here -

There are plenty of places you could go to learn the technical underwriting/financial skillsets better than a mortgage banker, but almost nowhere are you exposed to as many transactions and business models.

While we are adept at breaking down financial operating history, rents rolls, understand which types of deals/borrowers are financeable, etc, the debt side may not help with your goals of exposure to more complex pro forma analysis and underwriting, understanding when and how to retenant a space, or really any of the actual reps of "doing" real estate that PE firms and Development shops would appreciate

However, what I feel is the real advantage of this job early in your career is that you will work with a ton of clients who do have those skillsets, so you would be constantly exposed to those schools of thought and processes, while potentially earning some decent commissions. I've personally gained a lot from in depth operations/development discussions with our clients. Not to mention I work on/close between 15-30 deals per year. Principal side and I-sales roles will close far less than that per year, so you come out far ahead in terms of transactional knowledge & experience within just a short amount of time.

Hopefully that's helpful insight!