Sorry, I never have used Merlin. But here are free suggestions:
If you have a rare Rufous, get images, call a local birder connected with the IOU (Iowa Ornithologists' Union) to get confirmed and into Iowa bird official records. https://iowabirds.org/
An option for Merlin is eBird for a life list, Iowa list, etc. The eBird list includes the Rufous Hummingbird on the Iowa list (rare). You may want to transfer your list(s) to eBird. It is a fantastic platform out of the preeminent Ornithology department in the USA, if not the world, Cornell. https://ebird.org/home https://ebird.org/about/ebird-mobile/
Agree on this for the "rare' bird but was hoping for someone in Iowa to weight in.
We in MN had a quite rare Anna's Hummingbird in a front yard feeder last winter south of the Twin Cities. The chances of it being here were not great. And in November. And in the yard of someone who still had a feeder out. And a person who would know what it was. And that person having a doctorate with an emphasis in ornithology. And a person welcoming birders to her property to see the little hummer.