In the new system, the mentors are not allowed to make any changes on the `fixed blocks', i.e., Specialization 1&2, Computer Science Theory and Formal Fundamentals. These lists are fixed and unless changed by the faculty, have to be respected by everybody.
Adding more modules that are listed in a specialization to that block is no problem, since the given sizes are only minimal numbers of LP there. Adding modules to these blocks that are not listed there is impossible.
Hint: The Supplement block is quite flexible.