In general, there is no difference if you keep learning or making a pause, if some word is scheduled to be repeated in X minutes, you'll see it in X minutes. If there are no words scheduled to be repeated at the moment, Lingivst will feed you some new words in the meantime. If the intervals are too long it reduces the retention and that is probably what you are afraid of, but repeating too often is also not good. Your brain needs some time to soak the information in and to make a transition for short-term to long term memory.
At the moment, there is no way for you, as a user, to influence Lingivst's scheduling intervals, also there is no way to tweak your daily goals, all you can do is to trust Lingivst's proprietary, alien-inspired and AI-powered algorithm :-) It is promised it'll adjust itself to you learning and memorization patterns, so no manual control needed (that's why you have none). I don't see those claims to be changed any time soon. You might consider switching activities, like doing a short challenge or doing some grammar at those times, so you wouldn't feel like wasting your time and still learning some aspect of a target language.