How can I get back "instant" page-up/down, jump to top / bottom? (i.e. no smooth scrolling)

Just upgraded to a 2024 MBP (Sequoia) from a 2015 Retina (Catalina) and am getting mild motion sickness from the fast / smooth scrolling when I use the keyboard to page-up / down, and jump to top / bottom of the page. Old MBP (Catalina) jumps instantly. I've spent the past hour, or so trying to turn this "smoothness" off. I suspect that there's a terminal command that will do it, but my google-fu has failed me. I would be grateful for any help.