Should I apply Test optional to Amherst?

There is not enough information in your inquiry to make any determination if submitting a high SAT to Amherst ED would make any difference.

Since Amherst uses a holistic evaluation process that weighs your GPA, intellectual vitality, personal character, essays, talent, class rank, test scores (or lack thereof), recommendations, geographic location, volunteer work, ECs, work experience, first-generation status, and race, it's hard to tell whether you are strong candidate without your test scores or not.

About 1/3 of Amherst admits submit SATs and about 1/3 submit ACT scores so that means about 1/3 of admits do not submit test scores. That being said, I feel that if you are an International student its more important to submit a test score versus not submitting a test score because Int'l students typically have a gap in their common app narrative either in Course Rigor (lack of APs, IBs, College courses), ECs (lack of sports or clubs or volunteering opportunities). Secondly, Amherst is one of the few colleges that offer a limited amount of full-ride scholarships to Int'l students so they get a lot of applications from all over the world, hence the competition is fierce.

I would recommend that you retake the SAT in December for all the regular decision colleges you might be applying to if you do not get into Amherst ED.