As example, with this repository -
GitHub - RaananW/babylonjs-webpack-es6: Babylon.js basic scene with typescript, webpack, es6 modules, editorconfig, eslint, hot loading and more. Will even make coffee if you ask nicely. -
build without Inspector and additional scenes has the size of js folder about 6 Mb.
What else one may perform in order to make it as small as possible?
cc @RaananW
I would except around 1Mb for the smallest scene footprint not sure where you read the size from ?
Actually I tested and removed webgpu inspector and so on which could be split in their own module and the output is:
so I am totally unsure how you could have 6Mb which is bigger than the UMD version 
Are we talking production version or dev version? Sourcemaps are on? what is the size of the .js file alone?
The bundle size is OK (888 Kb).
My questions was related to the whole build size.
With sourcemaps disabled it is OK.
Thanks for the hint