Is 770 in Physics sat subject score worth submitting?

Well considering you were only 30p down from perfection, why not? But first and foremost, did you take an SAT? If not, perhaps you shouldn’t submit it for it may seem as though you prioritized your strengths over that of, what would be normally required, a college entrance exam (I assume you have though).

Further advice, take this from the Princeton Review: “ What's a Good Subject Test Score? It depends on the college of your choice. A good SAT Subject Test Score is one that fits within the range of scores your college usually looks for or accepts. Many colleges are happy with scores of 650 or above, but highly selective schools may want to see a 700 or 750—or even higher.” (https://www.princetonreview.com/college-advice/guide-to-sat-subject-test-scores)

And this from Ivy Experience: “ If SAT Subject Tests are ‘not required’ for one of your schools, remember this: taking and/or submitting your scores cannot hurt you; it can only help you. Again, the magic number is 700.” (https://myivyexperience.com/blog/sat-act-testing/sat-subject-tests-a-breakdown/)

So as long as you have an SAT score ready, I’d say “yeah” go for it! Good luck!