Remembering, referencing or even typing out the syntax, all the time is not great.
When within a $$ area, and the user types \, start offering autocompletion/syntax, like in IDE, snippets/function name completion.
Feature suggestion 2: Understand the syntax for brackets. For example, when typing \frac{, it automatically changes to \frac{}. If there aren't 2 pairs, even empty ones, it will be a fatal error in rendering. It should instead change to \frac{}{}.