If you enjoy the academics in your major (and no, I did not enjoy ChemE as a junior/senior), you can expect that your masters will teach you more about the why of all those equations you were taught without much explanation junior and senior year. You will also take a more rigorous math class, way more rigorous actually, and probably a lot of electives.
For example, for ME Masters at fairly prestigious school for, I took fluids, heat transfer, computational heat transfer, and also things like statistics for experimenters, space topics, energy engineering, controls, etc. For a thesis option, you may have to take specific classes since you will need specific skills to complete that masters.
Each school would be different, but in this case - you know the school.
If you go out into industry and start working some other specialty, there is nothing to stop you from having your employer pay for a few specialized classes related to your work. Tuition benefits are part of a good package for a young engineer and should provide for anything from business to engineering classes related to your work. Or, maybe your state school has programs that are affordable, or maybe an on-line class even without credit would satisfy your need to know (actually taking classes for credit sure helps your focus, but is also very restrictive on top of a full-time job and possibly family).
If you are not that enamored of the academics, but more interested in business, management, etc, which I think you might know even at 22, then I would think it would make sense to not commit to an engineering masters. I think this is why 4+1 programs rarely require a commitment from student or the college before junior year, need good to great academics and interest in academics rather than the diploma, the salary or the placement at a tech company so you can be a manager.