Take Chem test tomorrow or wait until more confident?

My hs junior has had one year of regular chem and is in AP Physics 1 this year. She’s registered to take the chemistry subject test tomorrow but has only been scoring 650-700 in the practice tests (mostly Barrons but one official former test was 650). Wondering if it’s worth bothering to try tomorrow or if she should bail for now and work on the material again next time there’s a good chunk of free time, maybe winter break. (She’s got an 800 math 2 score and is signed up for the ‘regular’ SAT in October so ticking off the other boxes, too).

I guess it boils down to: a) if she gets like 680-700 or so, is there anywhere that would want to see a SAT 2 score where that’s high enough anyway (looking at UC system, Tufts, Vassar, Brown, Rochester, Wesleyan, Reed, Oberlin, Carleton, CWRU, maybe a few more depending on how SAT goes and how junior year grades go, for likely math major). b) If it is in the 650 or so range, we can just opt to not send this in almost every case, right? Does anyone remember off the top of their head which schools require ALL scores to be sent?

Thx.