The Kha extension pack does work out of the box for plain Kha projects, but not Armory projects. I think it has a problem with armory games because the build folder isn’t build it is build_project_name/debug.
I also tried to figure out how to get just the normal Haxe completion provider to work. I tried to set the display configuration to the project-krom.hxml file generated by a Kha build. That almost works but it won’t find the krom-resources/files.json file unless you modify the export path from to include the full path from the project root instead of the relative path from the .hxml file. ( For example, -js build_project_name/debug/krom/krom.js instead of -js krom/krom.js ). After that completion will work if you use the normal Haxe plugin.