What are the letters of ikhfaa besides "seen" and "baa" required for the complete ghunna?
Any time there is an ikhfa' of the noon or meem, the timing is always complete
for the ghunnah.
So all the lettters in which the noon saakinah has an ikfha' with, have this timing of complete ghunnah.
For the noon saakinah they are the letters:
Also the iqlaab rule (noon saakinah changed into a meem saakinah) and al-ikhfaa' ash-Shafawee rule (meem saakinah) have an ikhfa' with the letter
, so also have the complete timing of the ghunnah.