Answered by Shaykh Faraz Rabbani
If some one has memorised the mufassil part of Holy Quran and want to recite it during prayer, can we read Surah after surah in each raka’. If not then do the prayers done in this manner need to be repeated?

Assalamu alaikum wa rahmatullah
There is no harm in doing this when praying alone. When leading others, one should observe the moderation and sunna of recitation clarified by the scholars from the Prophetic teachings.
And Allah alone gives success.
Faraz Rabbani