If the on-the-job undergraduate diploma takes the engineering route, engineers can only be evaluated at most, and senior engineers need full-time undergraduate diplomas.
As for on-the-job graduate students, it is basically useless. It's just that leaders or people who want to be leaders gild themselves to save face.
If possible, I suggest you take a full-time postgraduate exam. If there is no agreement with the original unit, you don't have to go after graduation. Many of my classmates and colleagues took the exam like this.
If you want to go back to work in the railway department in the future, it is recommended to take an examination of Southwest Jiaotong University or Dalian Railway Institute.