thanks alot, much cleaner than the kludge I'd been using! And judging by ivy's documentation, I'd expect this to work since ivy apparently supports alist candidates. On the other hand, when I tried it out I ran into type errors complaining about the symbol information being a hash table instead of a list; as far as I could see so far, every candidate (textual-representation . symbol-information) is passed wholesale to ivy--add-face instead of just textual-representation.
Tomorrow I'll rebuild all my packages from scratch and try again just to make sure (or read through the relevant parts of ivy but I think I won't get to that before the weekend), but could you please tell me what ivy version you tested this with? And did you use lsp-mode's new plist representation?

;; Version: 0.13.0

2. I haven't enabled `lsp-use-plists'.

I think I had some of these errors too, so you might want to wait before merging.

Ivy-update-candidates doesn't take alists. I've made an upstream PR to fix that.

this is still waiting for abo-abo/swiper#2716, or did I miss something?

@sebastiansturm it is.