Better placeholder support?
I don't know if this is in scope for an emacs LSP plugin, but when I use completion I often get things of the form ${1:SomeType} in my emacs buffer where Xcode would show a placeholder to be filled in. It would be awesome if that worked better. I imagine supporting this might need some help from swift-mode. If you look at rust-mode for emacs with LSP, it inserts gray text, that isn't in the file, showing types of things (and other information) everywhere in the buffer. I find that somewhat annoying but it would be perfect for placeholders.
See https://github.com/swift-emacs/swift-mode/issues/193, where the discussion has progressed, for examples and more detail.