I digged a little to see if it was doable client side in the mean time, looks like they are using Chart.js which doesn't offer panning or zooming. So no jury-rig as far as I know. There is a plugin meant just for that though https://github.com/chartjs/chartjs-plugin-zoom if they want to add it.
edit: side note, if the chart is cluttered by many categories you can click to toggle some on the top, it might help as it will rescale when possible
Additionally, we really need each data point to be a clickable link that actually takes you to the run in question. Super valuable for research and whatnot.
@chewchew @Daravae I have made just that! I too was annoyed by the lack of zoom https://www.speedrun.com/the_site/thread/ia1ph/ @Drakodan Not sure if that wasn't the case back then. But if you click on a point it does open the run in a new tab now.