Over 5 years ago, I wrote an article titled Track Adjusted Bounce Rate In Universal Analytics. It basically explored a number of different methods to tweak the Bounce Rate metric so that it becomes more meaningful in your Google Analytics reports. Now, writing that article wasn't necessarily my proudest moment. It's not because the solution was poor, but rather because I was suggesting it makes sense to tweak a metric. The concept of “adjusted Bounce Rate” sounds like the analyst is fixing a metric to be more beneficial to their cause, rather than fixing the business problem that caused the metric to be poor in the first place.
Google Tag Manager has a Trigger type which fires after a certain duration of time has passed on the web page: the Timer Trigger. The most common uses for the Timer Trigger seem to be either to send an event to Google Analytics after X seconds of dwell time (to kill the Bounce), or to defer a Tag from firing until some asynchronous request has completed with certainty. In the previous version of Google Tag Manager, the Timer was a separate listener Tag, which meant that you could start a timer based on a user interaction such as a click.