The do not licl out viable eggs. However, a new dad may nbe inept and accidentally boot them. Most of them get it right the second time and those that do not will usually get it right by the third t5y.
Also, some people place a cave such that it tilts down towards the open end. That allows the eggs to roll out with not much help. One way to prevent this is to place a small piece of slate or similar under the front end of the cave so that it tilts toward the back.
It is sometimes possible to put the eggs back into the cave. I have a turkey baster exclusively for use in tanks and I have used it to return pleco eggs.
Finally, a dad will boot eggs which are not viable. Even if we cannot tell they are no good, he can.