It seems that UnrealGameSync still needs engine's Source folder to deliver a precomiled build

UnrealGameSync tool actually requires Engine to have Source folder even when Precompiled zipped build is getting synced.
If Source folder is not on disk, UGS will sync it automatically.

It seems a bit counterproductive to me.
Whole point of using UGS is delivering precompiled engine to the content creators and having Source folder on their disk that alone takes over 10GB seems redundant and heavy especially for Indie developers.

Is it normal?
Are there any plans on improving this?

I solved this by delivering InstalledBuild to the team.
We change engine extremely rarely (for now) so we don’t need content creators to sync source files or compile engine.
I have two folders - one with source-built UE4 and one with InstalledBuild produced libraries.
We have virtual streams set up to only sync source to engineers and installed build to artists.