Currently in the list of 150 canonical texts before the 20th century, I do not have a category for Southeast Asian texts (or for that matter, Oceanian or Sub-Sahran African ones). Potential reaons to justify this is demographic strength, duration of literary traditions, etc.

In preparation for a future version of the list that may include some Malay texts (Malay/Indonesian being among the world's top 10 languages in demographic strength), I have studied Vladimir Braginsky's very informative work The Heritage of Traditional Malay Literature: A Historical Survey of Genres, Writings, And Literary Views (2004). 

Below are some of the more important blog posts I have written based in this study:

1. Malay Literature before ~1550AD

2. Traditional Malay Literature after ~1550AD:  Overview

3. Traditional Malay Literature after ~1550AD:  Key Works

4. Traditional Malay Literature after ~1550AD:  Key Authors

5. Traditional Malay Literature after ~1550AD:  Historiographical Works

6. Traditional Malay Literature: Most Canonical Authors / Works?

Based on what I know to date, if I were to include 1 Malay work in a World Canonical Text list of ~150, I would be including the work Hikayat Indraputra.