@John's reply is how I would handle it too.
With one addition perhaps, which is you will need to set up a new JS function which retrieves the timer value at any given moment. This function is necessary because Im guessing you have your JS trigger currently on a slide that Storyline stays on throughout.
Either way, you will need a trigger that is not constant (ie. part of the Interval ticks) in order to return the value.
So... 1 trigger counts down, while a different trigger returns values.
Thank you and @ John this does help my understanding for what was missing
