Shaykh Ubayd al-Jabiri clarifies that giving reminders between the units of the Tarawih prayer has no basis in the practice of the Prophet ﷺ, his Companions, or the early Imams, and is therefore considered an innovation.
What is the ruling on giving reminders in-between the units of the tarāwīḥ prayer without doing it continuously?
This is not from the actions of the Prophet ﷺ nor from the actions of his Caplihs, nor from the action the Imāms who followed them in goodness. Therefore it is from the newly invented [innovations].