A small update!
Thanks to the kind help of Greiga Master, the problem with ButlerTrans (our previous tool to extract/insert text) has been identified. That is, it doesn't actually update the jump commands. We're unable to contact the original author, so documenting the text codes and writing a new tool is what it comes down to. That's hopefully currently under progress, so we might just be one step closer to seeing the translations in action!
However, it still leaves the problem of those unusual images. To go into that in further detail, I believe the problem lies in those images being a single file, and not split into tile, palette, map or animation files as the others have all been.
My terminology might be a bit wonky, but I don't believe these images are 'compressed' as I've been able to view them correctly in Tinke/CT2. The issue is that, when I try to import any edits, (via methods that have worked for the other images), it becomes scrambled. Even if I were to simple export and re-import the image without touching it, for example.
I've got a GDrive folder
here with some files that can be used to test. The images appear in the bonus section of the game, gallery, which the save data is necessary to easily unlock.
The files come from the game's tex folder. These are originally .txc files, which ButlerTrans unpacks into .XTTN. I haven't tried editing the .txc as they were originally in the game, as I have not been able to view the images there, similarly to the .bgc and .dac files before they were processed through ButlerTrans and divided into tile/palette/map etc. Some of the images in the tex folder were divided by ButlerTrans, but those came out as empty files with 0 KB.
Here I've included a copy of st03012, which is one of the images I've been trying to edit. There's also the original image as I can view it in Tinke 0.9 (by opening as palette, offsetting it to 1C, then opening as tile and offsetting that by 48.) I've also sent my edit, indexed to only contain colours in the palette data. As you can see, I also cropped out the top line of scrambled pixels, as this is the height that matches the other images pulled from this game which previously worked.
The main thing that's stopping this project from being able to release are these technical difficulties, so as always, we'd be eternally grateful for any help! I'd be more than happy to assist or answer anything you might need clarifying.
Thank you for your time!