I am in favor of saving the package-selected-packages to a separate file and would also volunteer to make that change.

It's for these reasons I do not find that variable being saved in custom-file very useful:

- Sharing the custom-file across machines

- diff of that change is difficult to read as all package names are in one line. So I always blindly commit the change to that variable as I know that it will be auto updated by emacs when I install/delete the next package.

Saving this variable to a separate file makes sense to me because:

- This does not need to be git controlled ( I can easily gitignore this file ).

- All my machines using emacs can have their unique package-selected-packages file (for example: I don't install all work related packages on my home machine).