I grow sweet annie in a couple of my gardens , yes it will reseed probably more than you want.
I grow it for the sentimental value, my grandmother grew it , But I also like the smell .
I am able to keep it under control by cutting it to dry before the planrt goes to seed and leaving only one sprig to reseed , where I want it to grow.
Of course I am in the thought camp of anything not a weed is a good volunteer
There are a lot of re-seeders in my gardens