My apologies if this has been requested already...
IntelliJ IDEA and Visual Studio Code both have a feature, invoked by an easy to remember keyboard shortcut, that displays a search window where one can find and execute any editor command. The list of commands shown automatically updates as the search string is entered. In Visual Studio Code, the most recently used command is shown at the top of the list. In both, each command in the list also shows its corresponding keyboard shortcut.
SlickEdit does allow one to enter a command in the command line and SlickEdit will show suggestions. Unfortunately, it will only show suggestions whose command name matches at the start of the string. For instance, when I enter "space" in the command line, it only suggests "space-paren". It does not show command suggestions where "space" is not at the start of the command name. Offering suggestions that include the search string anywhere in the command name IMHO would be a significant improvement and bring us closer to what Visual Studio Code and IntelliJ IDEA offer. Displaying the keyboard shortcut to the left of each suggestion would also be a good improvement.