>> repeat.el doesn't describe the key binding, but it does say a repeat
>> mode is active. Kmacro is so smart that it aranges for the repeat key to
>> be based on whatever key the command was invoked with.
>
> Unlike `indent-rigidly', `kmacro' message
>
>   (Type e to repeat macro)
>
> is displayed on every keypress, so it's a good example.
> Now added in the following patch applied over the previous patch.

Here is another incremental patch that adds more messaging: