While I understand this is a proof of concept, is there any reason to use this instead of the existing patch https://www.romhacking.net/translations/2433/
That patch does not translate the majority of the terminology. To quote its website, 10% of item names and 68% of enemy names are translated there. This patch translates 100% of both. Some of the menus are easier to understand as well; that patch just has up and down arrows in place of buy/sell prompts due to space limitations. This patch has those options written out as Buy and Sell. This patch also uses a lowercase font, as opposed to the ALLCAPS in the current patch.
On the other side of the coin, more of the story is translated in that patch, but it still doesn't translate too far into the game and missing dialogue is a common occurrence. What dialogue is there was most likely directly entered from a hex editor as none of the dialogue has been repointed.
In short, while this patch doesn't translate the story or conversations, it should translate most of the rest.
That patch translates an amount of the story, and not that much else.