Over the years (since 2015) of maintaining Wikimedia's fork of Phabricator, I made numerous small changes which weren't upstreamed. Anything that seemed obviously general was upstreamed but most things were not. Many of these patches are specific to Wikimedia's use of Phabricator, however, there are likely to be some useful things that should find their way into Phorge.
One potential situation is patches where upstream Phabricator developers specifically objected to the change but where perhaps the Phorge community has a different opinion, more in line with Wikimedia's perspective than with Phabricator. I don't know if this will be the case but some of the changes might be worth at least considering.
For starters I intend to go through the list (P3) and identify anything that I feel would be potentially useful, then for each promising patch I'll either propose a new differential revision against phorge or I'll ask via other communication channels to seek feedback from the community.