I am by far a GSAP novice, but I have worked on a few kiosk interactives that clients have requested that draggable components work with multitouch. I am not sure if this will interfere with any other aspects of the gsap.draggable, but I have had some luck with using this little snippet I found somewhere a while back, sorry I can't find the original link. It allows the draggable to work normally even if additional touches are added during the drag.
function initDragContainer(){
let dragCont = document.getElementByID('dragCont');
let dragContParent = document.getElementByID('dragCont');
let yBoundMin = -(.clientHeight-svgContBox.clientHeight);
Draggable.create(svgCont,
{ type:'y',
bounds:{minY:yBoundMin,maxY:0},
inertia: true,
zIndexBoost: false,
edgeResistance:.75,
})
function ignoreEvent(e){
e.preventDefault();
e.stopImmediatePropagation();
if(e.preventManipulation){
e.preventManipulation();
}
return false;
}
dragCont.addEventListener('touchstart',ignoreEvent,false);
dragCont.addEventListener('touchend',ignoreEvent,false);