Submit just ACT, or SAT as well?

Here’s a variation of the perennial “to submit or not to submit” question:

ACT taken once - composite 34 (Math 32, Science 32, English 36, Reading 35)
SAT taken twice, 1. 1460 (EBWR 770, Math 690); 2. 1490 (EBWR 750, Math 740) so it’s 1510 superscored

Question: Should we submit just ACT, or SAT as well?
The argument for submitting both: it would show that the ACT score was not one-time luck.
The argument against submitting both: SAT scores, based on conversion tables, are slightly lower.

Most colleges on D’s list are very to extremely selective.

“Supporting”/“backup”/etc. scores aren’t really a thing. AO’s will see one number on their summary. The scores are pretty much equal to each other. The ACT is equal to 1500-1510.

The SAT Math is higher, the EBRW and Reading+English are a match (the comparatively lower makes the composite the same). I’d submit both and allow the schools to select what’s best. But if I had to pick one, I’d send the SAT. Especially if applying for STEM.

This assumes the school superscores. Obviously, the one ACT is better than either SAT if they only consider single sitting scores.

Thank you, @RichInPitt
STEM is not in the picture. She’s fluent in 4 languages, writes well, is very involved in many aspects of music, and is becoming more and more of a political junkie.