What I know from my personal experience is that the same meter is recited with slightly different melodies in different regions, and occasionally the same meter is recited differently in the same region depending upon the context. A good example of this is the meter Śārdūlavikrīdita. It is recited in the region of Maharashtra at least in two different styles in different contexts. There is one style of recitation of verses in this meter that are part of the so called Maṅgalāṣṭaka verses recited during weddings, and a different style in other contexts. One can get a sense of this variation from recordings available on resources like the YouTube. It is not clear to me how one would go about finding traces of such variation in pre-modern periods.