Rondo of Blood - English Subtitles while keeping Japanese audio?

[DissentKindly]

Hi everyone.

First off, I apologize if this was already asked or if I'm putting it in the wrong place, it's just the only reference to it
that I did find was from over a year ago and I did not want to "necro" that thread.

I recently acquired an RX after watching real PC Engine gameplay at a convention, where I saw Rondo of Blood being played in the original Japanese.
However, I sadly don't understand Japanese (yet?) and so I went to the English patch, which made me wonder if it was possible to keep both the English subtitles and the Japanese voice acting for both cutscenes and in-gameplay voices.

I have tried both bitcrunching and patching my redump-standard backup (cue+bins) which said the hash was incorrect, and another one of my backups which did work with the patcher but gave a load error when testing it in Mesen.

I know the patch keeps the original audio files, but attempting to introduce them and/or introduce wavs made from the original audio files in Audacity results in desynchronization and stuff like that.

Introducing the original audio files (tracks 19, 20, 21 iirc) to a ready-made patched instance works better cutscenes wise, but in the intro Death still talks in English, missing the point.

I am pretty much out of ideas at this point, and ripping with turborip is sadly no longer an option, so I registered to this forum hoping anyone could point me anywhere. (EDIT To reiterate: I am not asking for any rule-breaking files)

In short, I want to keep the English subtitles while maintaining the Japanese VA both in cutscenes and in game. The german can be original or PSP.

Thank you.