[zippie]

Would CTRL+X + CTRL+p/l/f be something akin to this? I use these frequently and have been quite content with their ability to provide in context completion.

[nickjj]

I don't know the inner workings of how it all works but I think with 8.2 there's an official API for floating windows now.

Where as before it was up to the plugin author to implement everything about it.

There's more details at: https://www.vim.org/vim-8.2-released.php