Static site hosting on GCP with SSL for basically free with Cloudflare

Does this process allows the use of custom domains?

For a long time now custom domains on GCS with SSL has been a networking "mission impossible" and just an absurd amount of work really.

I remember giving up 12 months ago, I can't remember why, and just deploying to Firebase finally. That worked out well...but much more work than it should have been. Particularly compared to just hosting on S3.