Not every SAT is exactly the same difficulty. Because of this, the College Board slightly adjusts the scoring for every test. If a test is unusually hard, you might be able to miss more questions and still get a high score. If it is an easier test, the scoring will be stricter.
You will not know how strict the grading is until after you take the test. That is why taking the test multiple times gives you a better chance at a good score. You are not just getting more practice. You are giving yourself the chance to take a test with a more favorable grading curve.
Some months tend to have harder verbal sections, which means a friendlier curve, while others attract more prepared students. If you look at past scoring tables, you can sometimes spot trends.
Plan to take the test two or three times. This gives you the best odds of landing on a test day where the math works perfectly in your favor. If your early scores are already where you want them, you can simply cancel the later tests.
Action step: Register for a few different test dates in your junior year. Do not stress if one test has a tough curve. Just prepare well for the next one.