I feel for you. I'm also in Washington state, and the eagles are especially prolific this year. I free range in my orchard as well and lost my little call hen last month to a giant bald eagle. Came right up next to the house to get her. I witnessed three additional attempts at my standard ducks down in the field, but was able to run the eagle off before any casualties. I know that they're beautiful and it's nature and all that, but I really wish we were allowed to treat them like other predators.
You may have a different experience, but I have never found reflective tape to be effective against aerial predators. The only thing that works around here is plenty of cover. I have a ton of river willow and weeping willow trees that the birds take to when they see a big shadow. We are also currently in the process of building a much larger coop so that we can keep them shut in for a week if necessary when the eagles are particularly bad. I say to give your tomato cage idea a try — I'd be delighted to hear if it works!