I succeeded, finally. What I understand is that applying a 0.1s transition in the inline style is necessary for Locomotive Scroll to remain smooth and not stutter during scrolling, especially for discerning eyes. Additionally, from my understanding, favoring divs over spans seems to result in less pressure during scrolling, perhaps due to the block aspect rather than inline-block. Even though you can set a span to display: block, divs might offer a smoother scrolling experience. Moreover, occasionally, and with caution not to overload the browser, I use the willChange: "transform" attribute in the inline style. These measures seem particularly effective for addressing minor shakes and offsets, especially with text elements.
Regarding the issue with background-color of sections and text invisibility, applying perspective in the Locomotive Scroll _base.scss file, to the [data-scroll-container], simply add perspective: 1px;.
Don't worry at all about the lack of support for Locomotive Scroll in GSAP; the free tools are already excellent. As for the GSAP smooth scroll, yes, I'm aware, but it's a licensed option, correct? I also wanted to know, the license with all GSAP tools, is it a license that one can use for commercial websites? And how much does it cost and for how long does it work? I'd like to learn more.
And thank you for the links and the response !