I’ve heard that saying you tested into a school (for example, imsa) it sounds appealing to colleges, is it worth it to try to get in?
I would only apply if you really want to go there, not because you think it will look good on your application to say that you applied but didn’t go there. Are you referring to the Illinois Math and Science Academy or some other imsa?
IMSA is an amazing school! Some of my friends go there and they love it. I agree with hedgehoglover. You should apply because you want to go, not just to apply. It’ll do you absolutely nothing to apply for the “fun” of it. Colleges won’t care at all. It’s worth it to try to get in if you love what the school has to offer. You should never apply to a high school just because of the college matriculation! IMSA has a great UI acceptance because they want to keep students in Illinois. Just the same, because the school has an acceptance rate and doesn’t take anyone, most of the students yearn to learn and strive to succeed. That’s why colleges like them. The school has a good reputation which is only made possible by good students. I hope that helps and makes sense… if it doesn’t make sense it’s late where I am 
I saw this and had to respond haha