musescore 4 change concert pitch

"please add the possibility to change the concert pitch. To 415 Hz, for example."
It's an open issue on Github:
[MU4 Issue] Regression: master tuning setting not implemented
https://github.com/musescore/MuseScore/issues/15566

"also please allow us to open several pieces in tabs rather than new windows"
This has been requested many, many times - but it's not easy to solve.
See Github:
Use single MuseScore instance for all app windows #12647
https://github.com/musescore/MuseScore/issues/12647
... and:
Open multiple files in tabs under a single app window #19136
https://github.com/musescore/MuseScore/issues/19136