Remembering what YAML key:value pairs have been used can be tedious.
Relying on tags / templates is not always optimal.
When adding a new key, or value to existing key, it would be great to have a suggest / autocomplete option available, that pulled from existing data in the vault.
A great example would be from GitHub - marp-team/marp-vscode: Marp for VS Code: Create slide deck written in Marp Markdown on VS Code
Hit Ctrl + Space within the front-matter or HTML comment to show the list of directives. You can peek the help of selected directive by hitting Ctrl + Space again.
For the ‘YAML frontmatter improvements’ Roadmap Trello card