Disabling the likes notifications is a recurring issue. Every time we make them go away an update happens and it breaks/reverts back to the "intended behavior" of the likes plugin. SJ brought this up to the developers of the plugin over a year ago and they said it will be supported in the next version. Until then it is a recurring and costly issue to fix since it requires hiring a coder to make the changes over and over again.
It is something that is on the todo list, but is of much lower priority than some of the other issues on the forum. In short, don't expect a fix real soon, Sorry...