I have used your built as inspiration, and it is basically done. However there is one problem that is plaguing me and I don’t know how to solve it and that is light bleeding in the corners.
I saw in your pictures that you partly have the same issues however it seems not as bad as for me. Did you do anything to get rid of this cross like optics?
I tried a lot from closing the corners with duct tape to little wooden blockers in the frame etc. but nothing seems to work really.
For a bit more context, there are lightstrips facing the wall. Most of it is under opaque cove. Also you can see my experiments blocking some of the corners with tape