Yes, so for example the skill Crew training retains maximum effect up to 240 DP worth of combat ships in your fleet. This is 60% of the vanilla maximum (and according to
the last patch notes the default) battle size.
Now if you for example have changed your game to use 600 battle size instead, normally the skill limit would remain at 240. What this mod does it adjusts the skill limit, in this case, to 60% of 600 -> 360 DP. It will also increase the number of allowed officers.
This mod does not change the vanilla ship limit of 30 for the players fleet.
Basically it brings fleet skills up to par if you play with a modded battle size value. Or constrains a bit if you play with a <400 battle size.
Does that answer your question?