I’m going to echo the recommendations that your daughter decide yay/nay on ED only after revisiting her top contending schools in the fall. And by revisit I mean take a serious look, get as deep into each school as she can manage. Visit classes, try to connect with department faculty, try to arrange lunch/meals with students in departments/majors of interest, try to meet with a student in the clubs that interest her, and especially try to schedule an overnight if possible. Unfortunately CC does not offer official overnight visits but if she knows a current student she can arrange an overnight on her own.
Colorado College has a unique vibe for a variety of reasons and any student considering ED should make an effort to spend some extended time on campus. So much to consider- the block plan itself, the location in the Rocky Mountains, a liberal minded campus in the heart of a very conservative small city, and of course the finances. CC does give out some merit but it is limited to a handful of students and I believe it tops out at $10K. Anyone who applies as a full pay student ED to Colorado College should assume no merit aid since an acceptance is binding and merit aid is unlikely.
If in fact CC still remains the top choice, and it is affordable with no expectation of merit aid, then by all means pull the ED trigger. If other schools become contenders for her after fall visits, however, she should be thankful that at least CC has the EA option. I agree that for better or worse there is a strategy with ED and that applicants should be aware that while it can confer an admissions boost at some schools it can also be “wasted” at others when an “average excellent applicant” with no hook from an overrepresented admissions pool is competing with kids comfortably in the top 25% GPA/Score range. Only you and she can decide what her chances are at a school like Brown or Tufts where the top end applicants are so strong. But I believe at Colorado College an ED application from an “average excellent applicant” will see an admissions boost.