How to import a "score in C"

So, I have a third-party application that generates musical content (https://github.com/ciacob/maidens, if anyone should care). Its generated scores are "written in C", in good old atonal tradition, so that all parts are expected to sound where they were notated.

For example, a notated C# in second octave, on an english horn, is expected to sound precisely there, and NOT as a "middle F#".

Now, if I export that to Music XML and open into MuseScore, that english horn plays a "middle F#" (F# in the first octave), no matter what position the "Concert pitch" toggle button is in.

Thanks to anyone looking into this. Attached is my Music XML file, if anyone cares to play with it.

I tried to toggle the "Concert pitch" button ON before importing my score, no use.

I tried to go in the english horn's staff properties and set its transposition to "perfect prime", but that permanently transposes all my english horn part down a perfect fifth, and then I had to select all english horn notes and transpose them back up, a perfect fifth.

Copying from a copy of the score with "Concert pitch" OFF into a score with "Concert pitch" ON didn't help either, transposition still occurs.

Is there a hassle-free way of telling MuseScore to just let me be, and pretend there are no transpositions, for any of the parts in the Music XML scores I am importing/opening?

Let's take (the infamous) Finale for example, which does it right here, actually: in Finale, if I import a music XML file, then copy everything in it and paste it in an empty file that has "Display in concert pitch" turned ON, NO TRANSPOSITIONS WILL OCCUR.

Can we have at least that, please?

You know, writing scores in C is a thing, since the dawns of the last century, after all...