In this paper we present an update on the South Indonesia obsidian interaction sphere. This interaction zone spanned from the island of Pantar in the West to the small island of Kisar in the East. Although obsidian utilisation has a significant antiquity in the islands with local obsidian being exploited in pre-LGM times, dates for the start of the network have only been pushed back to 15,000 years ago. We were able to detect obsidian transportation to small islands in the network, which might align chronologically with the emergence of this interaction zone. Prior results showed the utilisation of three unknown obsidian sources (Group 1, 2 and 3) with an additional three sub-sources suggested. It can now be confirmed that Group 3a, b, c, all originate from the same lava flow, close to the village of Kulunan on Alor. This paper will focus on new obsidian data from the Makpan site in Western Alor. This site has now been dated to more than 40000 years ago and it showed an abundance of obsidian artefacts. The obsidian has been sourced predominantly to Group 2, however, it shows substantial in-group variability which gives interesting new insights on the use of this obsidian source in the Terminal Pleistocene and beyond.