It's a known bug with the 2016 version. There's no workaround. Thankfully this feature isn't essential.
You can simply export models with `Use Mopaq Textures` option checked, and then put them to a map/mod archive manually.
See https://mapster.talv.space/star-tools/Tool_ExportFloater.html for details:
> ... Commit behaves as if Make DDS Files and Use Mopaq Textures are both checked, and Cache DDS Files is clear.
0.953782239916912