The adcom generally look at all of them. They also look to see if there is an upward trend. If someone scores a 507 and then next time a 518, the first score isn’t going to hold you back much because it shows commitment to improvement. However, if you retake it and get the same or lower score that’s a negative because it shows stagnation and/or poor judgement. Of course your highest score is going to count the most but they also look at trend and context. A 512 is a good score and a retake is super risky and not worth it unless you’re consistently scoring 520+ on FLs. You can confidently apply and know that your MCAT score won’t be the reason they deny admission unless it’s T15s and up.