When scrolling arbitrary text on a computer via keyboard, I generally become mildly frustrated hitting Spacebar, PageUp, and/or PageDown because I lose continuity with what I’m reading. (Perhaps the momentary 60hz blur makes it worse?) I attribute that to having a hard time identifying where I last read.
If there’s a dedicated button to scrolling, consider having an adjustable distance. EX: 100% screen height down, 95% screen width down (keeps a sliver of the last page), or 80% screen width down (keeps a chunk of the last page).
If you’re working with a touch display, perhaps a hold-and-drag-to-scroll feature could work? Have no indicator when pressed and only refresh the screen when the user lifts their finger. (It’s certainly not ideal to provide no feedback that it’s being used. But it may be useful to a user aware of how it works. Would probably need a training demonstration in-device like what older operating systems had.)
Perhaps a dedicated scroll undo button? For when one makes a mis-input and wants it back where it was. I know I’ve seen my grandma get frustrated at that sort of thing on desktop/phone where it’s quick to fix.