The patch is v 1_40 and has been comprehensively re-edited and tested to about 60% through the game, so I figured it might be in good enough shape to share. (1_40 should be uploading to RHDN today, 10/17/18.)
http://www.romhacking.net/hacks/4171/
Screenshots:



Its primary goal: restore every mistranslated connection to the other PS games, to and ensure the main story & series themes best match the original Japanese.
Its secondary goal: make the game’s script more colloquial, fun, and emotional, from NPCs to key story moments.

More screenshots and commentary at the project page: https://gamesdonelegit.com/phantasy-star-iv-generation-4-retranslation

Thanks to The Cutting Room Floor as well as lory1990's Japanese skills -- and lory1990 also made a bugfix patch for PSIV that I've included in this release, along with creating the disassembly of PSIV that even made this project possible.

Vivify, who also has worked on PSG1 & 2, has also helped me out a great deal too, and also did the original ProperCaser mod for PSIV.
I really enjoyed putting this together, and hope it gives fans either an excuse to play through such a fantastic game again, or give new people an excuse to give it a shot!
All my contact info is in the readme, etc., so if you have questions/comments/bugs, feel free to send! Thanks for everyone to keeping the memory of the classic PS games alive!