Is it possible to include newer terrain data from the Japan Aerospace Exploration Agency also known as "ALOS World 3D - 30m" (AW3D30) ?
https://www.eorc.jaxa.jp/ALOS/en/aw3d30/index.htm
This is the most recent DSM (digital surface model) from 2018 that includes fresh & up-to-date vegetation, buildings and other man-made objects. Some of terrain data is missing (it's marked by black color on the map), but mostly it covers >90% of the Earth. You need to register on the website to download tiles.