Special text "Solo" for the instrument in an orchestra

Your idea

I suggest creating the solo text in the palette, which allows a particular instrument to sound louder than other instruments
I suggest the following notation options.

1. To designate individual notes or phrases as the principal line, Schoenberg’s Hauptstimme (principal voice) sign H may be placed directly above the notes to enclose the prominent material. A secondary voice, Nebenstimme, is notated as N . These signs are so commonly used that they require no further explanation:
   
2. Alternatively, square brackets alone may enclose such material, as long as their function is explained in a preface (or staff text above/below):
   
3. Text solo / sola / soli / sole (depending on gender (feminine or masculine) and number (singular or plural)) above the staff with an invisible line covering a certain passage:
   
   At the same time, feminine instruments (viola, trumpet, tuba, harp, celesta) should be marked as sola (singular) or sole (plural), and all others as solo (singular) or soli (plural).
   I recommend implementing methods 1 and 2 in the form of the following line:
   
   At the same time, the user should be able to change the style of this line in any of the three ways listed above.

Problem to be solved

There are times in the orchestra score when there is an inscription solo above a particular instrument. This means that the instrument should stand out from the rest in sound, that is, it should sound louder than the rest, and the rest should be modeled so as to sound quieter.

Prior art

No response

Additional context

I think that it is necessary to take into account such a designation-instruction as in rilievo (translated from Italian as "in relief"), which means a prominent line in the string section, as well as a soloistic manner of performance for a soloist in a multi-player section.

No files, tests, or entry points are named in the issue. Start by clarifying which of the three notation approaches is required and whether playback-volume behavior is in scope; done should include an agreed palette item and notation behavior.