Great NEWS! Autodesk have released their OPEN-SOURCE version of their usd import export code for 3dsmax. This is really powerful and shows us the possibility of true open-source universal USD support. Please consider using their usd exporter over our connector at this time.
GitHub - Autodesk/3dsmax-usd: OpenUSD plugin for 3ds Max
GitHub - Autodesk/maya-usd: A common USD (Universal Scene Description) plugin for Autodesk Maya