It is impossible to mechanically do any sadhana for a long time daily, unless we get spontaneous blissful remembrance while doing it. So that should be our goal. Due to the forgiving and offenseless nature of Nitainam, Nitai Gunjan is one such sadhana, which makes even the most offensive person experience infinite bliss and love from the beginning to the end, while doing it.
When we wholeheartedly practice a means like Nitai Gunjan to make our Harinam pure, it means that it is extremely important to us that we chant Harinam offenselessly, not that we are minimizing or replacing Harinam. In fact we do Gunjan because Shuddha Harinam is our top priority.
Approaching Nitai means going to Nitai Gaura Lila, because Vrindavan das said that Gaura Lila lies safely in Nitai’s custody. Nitai is the topmost devotee of Gaura & Radha is of Krishna. So Nitai Bhakti includes Gaura Krishna Bhakti, just like Radha Bhakti includes Krishna Bhakti.