Is it better to continue with a certain amount of supererogatory prayers while engaging in dhikr and Quran recitation, or to gradually increase supererogatory prayers until they encompass all times?

It is recommended for a Muslim to perform as much supererogatory (nafl) worship as they can consistently maintain without leading to boredom and then discontinuation, for a little that is consistent is better than a lot that is cut off. It is disliked for a Muslim to commit to a supererogatory act that they know they cannot consistently maintain, as this may lead to boredom and an inability to perform what is more prioritized in Islamic law.