Back in the day, we used to talk about "big C" ChemE's and "bigE" ChemE's. The latter was far more common, while being one of the former, I was and still am a freak.
It's been my experience (20+ years in large and small companies) that you will be able to do more chemistry if you work for smaller companies. Bigger companies will fit you into the big E box like they do with all the ChemE's, and there you are. Smaller companies, and startups in particular don't have the luxury of that, so if you can do both the chemistry AND the engineering, you will be viewed favorably and get to do what you want.