Which is more befitting for a Muslim: learning the tajwid of the Qur'an or its tafsir, if he recites the Qur'an with little knowledge of tajwid?

Allah commanded the beautification (tajwid) of the Quran. Engaging in the science of tajwid is a communal obligation (fard kifayah). As for practicing it, the early scholars of Qira'at (recitations) and Tajwid held that adhering to all principles of tajwid is obligatory, and one who neglects it is sinful. However, later scholars differentiated between a religious obligation (wajib (definition) shar’i), whose neglect leads to altering the structure or corrupting the meaning, and a technical obligation (wajib sina’i), for which one is not sinful if neglected. It is best for a Muslim to combine learning the tajwid of the Quran with its interpretation. If unable to do both, learning tajwid is more prioritized because neglecting tajwid for one who is capable of it may incur sin.