Well if you connect a Noise node to the wall material in the tpp project, and set its scale to 1 , it should present you a very loud noise, so you can test that. But of course any noise texture will work, just make it dense and the pixels next to each other should have high contrast. Obviously it is just a synthetic test to display one of the many flaws of TAA, but you can interpret these results similar to a high detail texture, or grass etc where the same issue will apply, but less visible, comparatively.
Here this image will display two more issues:
The car is moving relatively fast about 200km/h, and you can witness the SSR is bending towards the viewport. Hard to see, but its there. Then, just look at a textures around the ghost shape, it is actually a bit brighter than it should. As you have mentioned there is an anti ghost exists which will treat and replace the car’s history areas with the new input, but it cannot adjust the content to the invalid road texture around, so it have became darker. Hence the ghost in this case.
These issues along with the noise problem can be handled, but the solution is invalid.
The problem you are working on appears to be a fourth one, that may turn out to be the malfunction of the motion blur or the taa, maybe both. I actually been thinking that why the issue does not present itself with FXAA to a certain extent (without propogation), since FXAA should also present some synthetic pixels here and there for the motion blur to sample the wrong data.