My S got accepted to the Purdue Polytechnic for Energy Engineering Technology his 2nd choice. His first choice was Chemical. He has other options, but he is inclined towards Purdue so trying to get an idea oh how difficult it would be for him to transfer to college of Engineering if he decides to go to Purdue.
I would encourage your son to reach out to the CoE and speak to them directly about how many students successfully make the transfer from polytech. I would also ask about the difficulty in registering for the necessary intro courses from outside of the college. My D knew only a handful of students who successfully transferred into engineering and I think most of them came from the College of Science or from Exploratory Studies.
My understanding is that CODO into engineering is quite challenging.
Google “CODO into Purdue Engineering” for the requirements. A student switches to first year engineering (after a minimum of one semester) and then must complete the FYE curriculum to Transfer to Major. My understanding is that there are many applicants and not many spaces, so the GPA requirement is quite high.