The idea behind this hack comes from some old tutorial byuu published years ago on his website (which can be currently found here) involving prerendered tiles and DMA transfers to avoid actually drawing anything other than pre-built sets of tiles for almost everything. This handy trick allows proportional fonts with almost no lag whatsoever and it can be applied pretty much to any game in need.
Most of the text used in this hack is either lifted from FFIV: Complete Collection, tweaked from there, or quickly translated from the original messages. So, in a manner of speaking, it can't be considered a real retranslation, even if it's based on a vanilla ROM of Final Fantasy IV (J). I'm not sure myself if this should be posted, when completed, to the hack section or as a translation; feedback on this would be appreciated.
The project is completely open source and can be modified by anyone who would like to either improve it or use it for a derivative translation / hack. You can find sources compatible with xkas plus here: https://github.com/Gemini-Loboto3/prettify
For the moment it covers mostly in-game menus, shops, and Namingway screens, but I'm planning on expanding it to dialog and battles. It also includes a nice expansion to player names, now supporting 8 characters instead of 6. I already have a full disassembly of the ROM ready to roll and I have located most of the stuff that needs to be changed, meaning it's a matter of time and brainstorming.