Octave-transposing clefs
Here is a simple score, with the clefs left as Musescore created them:
Now, Elaine Gould's Behind Bars, which I understand is the authoritative book on musical notation, says that octave-transposing instruments should never be written at actual pitch, but it will be understood that they sound an octave higher or lower than written She says that use of the octave -transposing clef (with the little 8) is optional, but recommended because it "makes it easier to identify position of instruments with such transpositions in the score."
So either the absence of the octave-transposing clef in the piccolo part, or its presence in the bass flute part, can be justified. But what I find confusing, and what can get very confusing in a more complex score, is the inconsistency. Since using the explicit octave-transposing clef is optional but recommended, why not always use it? It seems like the worst case is to use it sometimes, but not always.
Comments
I would agree that inconsistency is the worst case scenario. Consistency is a must.
In my experience, octave changing clefs are not used in most published music. Contra Bassists and piccolo players are not used to seeing the 8 above or below their respective clefs. Using the octave changing clefs causes problems with some instruments because not all clefs come in octave changing varieties, so clef changes for those instruments are very difficult to notate in MuseScore if you start with an octave changing clef.
Octave transpositions are an area where there are two different schools of thought, and plenty of published examples following each. Gould is coming from one of those two schools, but MuseScore is mostly coming from the other. We did change some things to work more like the other school, for those instruments where it seemed the majority of publishers worked that way, but for other instruments the consensus isn't as clear.
Some of those are in transition - some of the flutes in particular were changed for 2.2, I believe.