I did generate a sample return to test this. First thing I notice is that Family Link does not transfer data. Screen 43, you have to input manually, just like in olden days. My guess is that will be updated someday. I don't know your figures, but what I used originally was not high enough to affect a change. I increased the child's interest income to 15,000 and did generate a difference of $60. 

It does work. Not very elegantly and takes more effort than it should, but it does work.