I deleted unity cache and put uncompressed translated .bundle for Gracie inside the game's content folder, and there is no artefacts. So unity is okay with modified but uncompressed by UABEA .bundle files. I'll decompress all translated .bundle files and reupload whole translation.
Funny thing I tried after installing the uncompressed translation.
I went to the cache folder and noticed the files are a smaller size, although still about 20MB bigger than the original chinese version on average.
I copied the cached _data file in the respective girl's directory and replaced the bundle file with it, renaming and all.
Afterwards the game and album still worked fine, while shaving off a couple dozen MB per file.
It's kind of annoying work though because the cached files don't have the girl numbers, but the internal directory matches the bundle name.
Not sure it's worth the effort, but it's an option for anyone who wants to save a couple of GB.