We are releasing the ability to overlay images and videos in 4.24 next week! You can try it out now using the /next early access release. The functionality is even better than 3.x… you can overlay both images and videos in 2D and 3D, add/remove multiple images on the fly very easily, and use it with other 4.x capabilities like layer blending (note: so far you can only do layer blending with MediaLayers in 2D).
Here's a simple example: https://codepen.io/U_B_U/pen/MWQGWdb?editors=1000
Drop me a note and let me know how you will be using it :)