So after trying various things I've spent the last day or so grabbing and restoring the PSX font by hand using the SeeD Hashmap, thankfully the text palettes all line up perfectly with the original PSX text and so the colors and usage and everything seem to be displaying properly at fullscreen
However, as you can see there is something wrong here, the Icon sheets that SeeD uses don't map 1:1 to the original icon palettes like the fonts do, which is why we get this white text. I have been able to fix 95% of that before I took this screenshot but I was still finding every so often an arrow or a symbol in different circumstances would be pulling from the wrong palettes and I decided that rather than pick through ever intance of misuse in the game I'd rather ask here instead about how I might go about using Tonberry and Berrymapper to get the Icon palettes to match 1:1 with the game defaults. (This is to override the Icons in the Hires folder with the original Icons, they've been split into quadrants to match the Hires versions)
I do still wish I could find where the game decides to use "B10" and stuff to try and replace that text with the PSX buttons, that would be the Icing on the cake, the work arounds are messy and frankly don't look very good even when done properly to me. I'll keep digging.