tysm for your answer, and your welcome 
this is a “handle inputs locally” type of approach, and while it’d allow to create custom functions for zooming and scrolling within the canvas, it wouldn’t help with browser-based gestures like pull to refresh, or scroll to make the url bar disappear (which I admittedly didn’t mention as something I’m after, my bad).
the reason I asked here is specifically because I’ve found posts that ask the exact opposite question, meaning how to disable all of these touch controls, like this one, this other one, or even a third one (that I can’t link because my account is too recent) which is called “Restricting touches to be used by P5.js and not the browser: possible?”.
these posts are all from 2020-2023, so could this possibly have something to do with the V2 of p5js?
thanks again!
edit : converted my js to p5js v1 and now it all works fine, so I guess that’s one way to get it done, but now gotta deal with v1 issues that were fixed in v2 