You could write your own in material refraction instead of using the default refraction. Thankfully you can read the in engine’s shader code for the refraction to get the exact formulas they use. The only tricky part is you need to make some adjustments for screen resolution, aspect ratio, etc.
Instead of sampling the scene directly and then applying the refraction, you’d need to flip it across it’s axis and then apply an offset (so that it’s sampling roughly the same area of the scene as before it flipped).
Imagine your ball is in the bottom right of the screen, if you simply flip the axis before refracting, it will sample what used to be in the top left. Thus you need to flip it, and then shift it. You can shift it all the way, or just always align the refraction to sample the center of the screen to reduce the likelihood of sampling off screen which will cause artifacts.
Another downside is that an in material refraction shader can’t do cumulative refraction - in other words if you place two transparent objects in front of each other, instead of seeing the combined refraction of both, the second object will be invisible due to scene sample omitting transparent objects.