Should I take Latin subject test as a senior?

I took Latin 2-4 my freshman-junior years and I’m not currently taking any language classes as a senior. If I studied, would taking the Latin subject test be helpful in getting out of my college language requirements or reducing them? And what score would I need for it to be helpful? It wouldn’t help me in admissions since my apps are in, but I want to make the language requirement as easy as possible in college

It depends on the college. I think public universities will be generally more likely to exempt you from language requirements with an SAT Subject Test score than private schools.