UX improvement: Show word completions and blue box hint as you type

In VS Code, IntelliJ, Eclipse, and other popular IDEs, completions are shown opportunistically as you type, along with any associated call signatures and docs snippets.

For example, in the screenshot below, all I had to do was start typing "so", and VS Code proactively showed a menu of matching completions, along with a docs snippet for the top match:

It seems like it it would be a simple change to similarly show the word completions menu and the blue boxes opportunistically in DrRacket, and it would lead to a significant UX improvement. The current behavior makes it hard to discover these helpful features. What do you think?

Context

I'm currently taking http://dabeaz.com/sicp.html with a number of other students, and none of us (including the teacher) even noticed the blue boxes until I asked if there was a way to show a docs tooltip in the Racket Slack (assuming there had to be some way), and got the answer.

The issue names no files, tests, or entry points. Start by locating DrRacket's existing word-completion menu and blue-box documentation features, then clarify the intended behavior for showing them while typing. Done means completions, call signatures, and documentation snippets appear opportunistically without requiring a separate discovery step.