There is a lot of interest and discussion in #38040 and #56010 when it comes to showing/hiding details of a quick info request. In microsoft/vscode#195394, we have a proposed client/editor API to serve up such an experience, and we'd like to provide it.

There are some questions that still need to be answered and prototyped. For example, what precisely should be expanded? In some cases, a type reference can be expanded into its structural form. In others, an elision (...) can possibly be shown. Whether this is always desirable is questionable.