I love your post so so much. Allowing a kid those extra few months to evolve is priceless. Kiddo has such a better understanding of what he is looking for now than he did in October and will have an even better idea in April. 6 months is a pretty significant percentage of a 17 year old’s life - a lot changes.
To us, if time came at the cost of a marginally improved chance of admission at a reach, so be it. ED is alluring, but for our kid, not worth it. If a school doesn’t love him enough to admit him in the RD round, their loss. 
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