Problem/Motivation
Drupal supports compressing aggregated assets with gzip.
It would be nice to also support brotli, since it provides better performances.
advagg provides this functionality but only on non-aggregated files.
Proposed resolution
AssetDumper could be patched to also create brotli files.
Remaining tasks
I will submit a patch.
User interface changes
A new option will need to be added to /admin/config/development/performance.