No need to repost, just add any additional information in the comments section of the original post. You can also go into your profile settings and add your USDA zone and state to your profile and it will show up with your name.

I don't think you are going to get any different opinions by reposting. Basically, the bed is already quite full and is going to get fuller. A small dark leaved perennial might be squeezed in but not another shrub.Your original post.

With that deep purple maple there and planning to gradually get a lot bigger I can't see the value in adding something else that is dark. If instead you fill the entire rest of the bed with things as non-dark as the blue fescue there might be just enough of it to start balancing the visual statement made by the maple.

Notice how much space is taken by the yellow conifers and the blue fescue as it is yet still the maple registers as a pretty big area of darkness.

Don't give up on the boxwood yet. Prune out the dead and let it fill in.