IB internship to non IB offer

Hey guys, long time reader but new to this feature. I am hoping to get some advice on my current predicament. I graduated from a non target with a 3.5 last may and turned down various offers in favor of pursuing IB. I have since then very successful completed a Private Equity internship. Currently I am wrapping up an off cycle investment banking internship. My current internship is at a small 20 person boutique with solid deal flow ~40 deals annually in the 50 - 350 mm range. The bank made me a full time offer today. The issue is that they are not offering me an analyst role. The bank wants me to essentially work on training and leading the interns. I would also assist on developing research and other ad hoc project. Further, they mentioned that depending on my performance, they may be open to me interviewing during the upcoming summer. I have spoken with various mentors of mine and many have said that I should take it and keep on networking/ applying for IB. Thoughts? I am grateful for the offer but scared that it will pigeonhole me into admin like roles and make getting into bschool even harder.