I also love ray’s, but I get how it would be moomers. The last time I went to traverse city, the line wrapped around the entire fucking building. The ray’s near consistently has lines out the building in the summer.
In Indiana, there are 2 other places that should be on your list. There’s Zaharako’s in Columbus, IN. And there’s Ivanhoe’s in Upland, IN (with 100 varieties of shakes and sundaes).
For Ohio, I highly recommend Weldon's in Millersport which is around a half hour east of Columbus. Family owned and operated since 1930. All natural ingredients. And they have among other fantastic flavors, blueberry ice cream.