Hi OsuBlake,
Sorry to ask, but like this screen with Locomotive-Scroll, the main intention was to find people who has already met this problem. I totally understand that GSAP does not offer 3rd party support. And basically I think it strange that GSAP use these librairies like here https://greensock.com/docs/v3/Plugins/ScrollTrigger/static.scrollerProxy() and you gave me the answer that "That is not GSAP, go ask to Smooth-Scrollbar".
I don't want to be offensive or else. I'm just a bit confused by your response