I enjoy using linked chests in train stations to avoid balancing problems. However there's one big issue that presents with them and that's that trains can arrive and try to unload, or items can try to be loaded, before the blueprint is finished placing. It would be nice if there was an option to allow merging linked chests even if both are not empty, and simply spill anything that doesn't fit in the resulting merged inventory. It's a lot easier to have robots clean this up than to manually fix up any train stations that got mislinked.