Wow very nice combo shade plantings .
I have the mini lace leaf maple tri color just like the one in your pic. And many similar hostas ..the deer ummm... ate them ....
Your maple trees are beautiful and a well maintained garden with loads of gorgeous healthy plants . The artful way you have added texture, color, height, space and diversity with shade plants and other elements added in the garden demonstrates the design blended with beautiful old growth redwoods , looks and feels of an enchanted forest .
Adding hydrangeas will add some clever diversity in color and texture. Many bi-color leaves too. They are a fav of mine here in the NW they are almost a must in gardens.