@Mom2aphysicsgeek, I am well aware of the option provided by GTECH to change branches once accepted. My D2 (she is a Sophomore now at GTECH) chose GTECH over UCB for this very exact reason. At UCB, it is very difficult to change from the College of Chemistry (for a ChemE major) to a branch in the COE. She wanted to have the freedom to change to another branch of Engg. easily if such need arose.
However, when D2 applied, she had put in ChemE as her first choice. I am fully certain that she would not have required the high credentials to have gotten into, say the College of Architecture as an OOS applicant.