On one hand, adding a whole mastery level to the skill planner sounds like a nice easy way for people to train all skills related to ship.
On the other hand, mastery levels are often not relevant, make for bad skill plans and may scare newbies that see that they need to train a whole year to master a certain cruiser, because it’s suggesting you to train multiple skills that take a whole month each just to get a smaller than 2% damage increase in systems that the player may not even be planning on using.