The two things that have helped me with scrolling Lemmy have been:

1. Setting the default sort to Top posts of the last six hours. I can still see most of the interesting discussion, but get down to newer, less active threads within a few pages. Then I want to give it a few more hours for more activity to form.
2. Setting a generous screen time limit of 2 hours a day. Combined with the first I feel a need to space out when I browse Lemmy to ensure I see most of the daily activity.