Is it permissible to vary the levels of recitation (Hadr, Tadwir, Tahqiq) within a single prayer, such that one recites in each rak'ah at a different level?

Reciting the Noble Qur’an is permissible with Hadar (rapid recitation), Tadwir (moderately paced recitation), and Tartil (slow, deliberate recitation). The latter is also called Tahqiq (verification/meticulous recitation). All these fall under recitation with Tajwid (Qur’anic phonetics and rules). It is permissible for a worshipper to recite in one unit of prayer with Hadar, in another with Tadwir, and in a third with Tartil.