gsap.config({force3d: true}) only gets honoured on new tweens with untouched elements.
In my example, if you click on first element, then resize the window to >600px and click the second element, one uses translate() and the other translate3d(), now, if you resize the window (that changes force3d) and keep clicking on the elements they stick to their initial transform variant.
Mind, that each click creates new gsap.set or gsap.to animations respectively, so it's not reusing old timeline.
Is there a way to force 2d transforms in to 3d globally on the fly as new gsap animation instances are created?