The mod slightly changes trainer's AI packages so that most of them are available for training whatever they do unless they are asleep. Some of them are always available for training. 

This reduces the chance of schdule inconsistencies causing bugs preventing PC from accessing the training button like most infuriatingly happens to Marc Gulitte who can only train if he is sitting, but sometimes refuses to do so with a stand-up animation once you close the waiting menu box. Another example is Delphine Jend, who can only offer training while standing in a definite position in the guild hall forcing you to move her manually there or wait and hope that she enters the area. Additionally the bug occurs to all spell-sellers in the Choroll guild. 

Another pain in the ass is to catch thieves guild trainers when they can train you. Now most of them can even train you when it's bed-time.