If I were a PPL holder with a night rating doing my ATPL groundschool, and I got a multi-engine rating and Instrument rating while doing said groundschool, would I have to redo them for CPL i.e. are they the same ratings for PPL/CPL, and are they transferrable?
If you were a PPL holder with a Night Rating and studying for your 14 ATPL ground school exams. Then what you're doing is combining your CPL and IR theory into 14 exams (basically).
So armed with a Class 1 medical / PPL + Night / ATPL GS complete along with the minimum hours you'll be looking to gain a CPL (replaces the PPL) and a MEIR. Along with a MCC you'll have a fATPL.
Goof luck