[Musicxml Export] - Unable to export images

As for me, the status is 100% Block, but for development, I have to set as major.
The export of compressed Musicxml (.mxl) doesn't contain any images, neither png nor svg. I attempt to transcribe this (and the other 3 parts) in braille:
https://musescore.com/user/34104354/scores/7848272
This is a commission from a blind pianist, so I must do it. However, the EMB edition has some symbols not available in Musescore, so the engraver made them as pictures. It is of no problem for doing this, but there are too many of them, 16 picture files and over 60 instances in the mscz file. If they could be exported in musicxml, I could have easily marked them in Musicxml file and apply correct signs in braille. But this is impossible, and I have to manually add staff texts with "img1" "img2" etc in the mscx code, which leads to fatal syntax error (because sometimes I don't know wher I can put the tag, there are lots of strange elements in the mscx code rather than the simple musicxml structure), wasting my time and I'm still unable to do the job at all. Hope this can be solved in Musescore 4, then I can transcribe all scores with picture files.

Haipeng