Source fallback removal - unable to use dist (firewall blocks zip files)

As indicated in the blog post, I'm opening this issue to express serious concern about the removal of the source option completely. I understand there are risks, but our corporate firewall blocks zip file downloads, so we have to use source as the primary mechanism - otherwise, we will not be able to use composer at all.

https://github.com/composer/composer/pull/12698 https://github.com/composer/composer/pull/12885

Let me know what additional information would be helpful.