I do a double infusion on my calendula.. I have about 30+ herbs I do different things with from tinctures to infusions to salves, and I use Calendula more than any other. The fragrance and properties just can't be surpassed IMO.
That being said, I use my infused oil a lot for soaps. If it's a single infusion the smell doesn't come through as much but the double does and its wonderful. I don't do a tea though as I like to use a milk with mine and the heat with the lye always does off things to my teas.
My caledula infusions are strong though after 'cooking' for weeks... if I use a clear oil like fractioned coconut oil, its almost a brown when I'm done, and it smells heavenly!