I can’t share my own code, but to see it in action in a demo go here:
Click on 'Start Starling Demo' and then on 'Benchmark', then Start Benchmark. Let it run on a PC with nothing else using up performance.
When I do this it manages over 14000 objects, i.e. textured sprites, moving and animating smoothly, drawn on top of each other so pushing up the fill rate. On my late 2012, so 7 year old, Mac mini (a PC that was slow when I bought it).
It works as they are all added to a Sprite and transformed together. Rotated and scaled rather than scrolled but the principle is the same. It’s adding and removing vertices all the time, as it grows and shrinks the number of images. But most of the images don‘t change; they are static in their Sprite container. Which is moved by updating its transformation, which means only a single matrix is updated every frame.
The code for that app is included with Starling, so you can look at its code to see how it does it. That’s why I know it’s possible in Starling to smoothly animate 10,000 or more objects at once, if they are move together in a Sprite.