As the title suggests, can I apply Early Action to other schools if I’m applying ED to Cornell?
Yes but only if it’s non restrictive early action. For example you cannot apply to Cornell ED and Yale SCEA. you can’t combine single choice early action with early decision.
However, you CAN apply to your in-state public university, for example, even though that may have an early submission date and it’s non binding and/or rolling admission.
My kid applied to UMich and UVA EA when she applied to Cornell ED, but she couldn’t apply to Georgetown’s EA due to GT’s EA restriction. You definitely can’t apply to any SCEA schools, due to their restriction. As far as Cornell (or any ED school) is concerned, you can apply to any other school, but once accepted by Cornell ED then you must withdraw all other applications. Most students would have their regular decision applications all ready to go, and if they should not get accepted by their ED school then send their RD applications. My kid saved over $1000 in application fees by getting accepted by Cornell ED. Of course, if you have any rolling admission school on your list or schools that would give you merit scholarship for applying early then you should get those applications in as early as possible.