Here is a test of the Feather UI scroller that doesn't prevent PopUpListView to open when scrolling. Because when clicking on the button, the scroller doesn't know yet it gonna scroll.

TestScrollPreventClick.hx

package;

import feathers.data.ArrayCollection;
import feathers.layout.VerticalLayout;
import feathers.layout.VerticalLayoutData;
import openfl.display.Sprite;
import openfl.Lib;
import feathers.events.ScrollEvent;
import feathers.controls.ScrollContainer;
import feathers.controls.PopUpListView;

class Main extends Sprite 
{

	public function new() 
	{
		super();
		
		var container = new ScrollContainer();
		container.height = stage.stageHeight;
		addChild(container);
		
		var fc = new PopUpListView();
		fc.y = 300;
		fc.layoutData = new VerticalLayoutData(100);
		fc.dataProvider = new ArrayCollection([
						{ text: "Please Select" },
						{ text: "test1" },
						{ text: "test2" },
						{ text: "test3" }
					]);
					
		fc.itemToText = (item:Dynamic) -> {
			return item.text;
		};
		container.addChild(fc);
		
		var fc2 = new PopUpListView();
		fc2.y = 2200;
		fc2.layoutData = new VerticalLayoutData(100);
		fc2.dataProvider = new ArrayCollection([
						{ text: "Please Select 2" },
						{ text: "test1" },
						{ text: "test2" },
						{ text: "test3" }
					]);
		fc2.itemToText = (item:Dynamic) -> {
			return item.text;
		};
		container.addChild(fc2);
	}

}