Is your feature request related to a problem? Please describe it.
Even for a simple document, when opening the toc, the real toc headings start way down at the bottom. The top half of the toc window (where most eyeballs/brain power is focused; this is supported by pedagogical research) is cluttered with help instructions/legend keys (I know there are options to disable them), and the real TOC starts way at the bottom.

Describe the solution you'd like

• Move the legend and keymap instructions to the lower half of the toc window (or make their position customisable by providing an option key for users)
• Fold it away by default (and provide options for enabling/disabling these folds).

This solution will remain compatible with the current vimtex options and behaviour.

This will result in a better UX.