I'd also like to know if it's possible to do that. But as I understand it right now, with KM you don't ask a user for a character of input, rather you let the key be the trigger for a macro. The macro I screenshotted in the post that you linked contains an image of the trigger that you would need to use. If you do that, you can access the value of the keypresses using the %TriggerValue% token. It's a different way of thinking, and may require you to rewrite your code.
A loop requires to know when to stop. When are you planning to stop the repetition you speak of?