You can’t currently adjust the thickness of the brace, except by changing the music font. You also cannot currently adjust the distance from the staff, but this will be possible in the next update.
To me, that depends on what each instrumentalist is playing. I often compose with percussion “stations” in mind for each player. For example, one musician may play bass drum in one section, then switch to glock or vibes in another. Meanwhile, another percussion in another station would be switching between orch. bells, triangle, snare, and marimba. In this case, I would love to bracket each station separately in the score, so it is very clear as a conductor which musician is playing which instrument.
Hope that helps, Daniel!
I’d like to second thiagotiberio’s request for percussion brackets. I’m working on a chamber orchestra piece with 2 percussionists, each playing a wide variety of pitched and unpitched instruments. The new percussion setup is working beautifully for this. But it would be even better if Player 1 and Player 2 each had all their instruments bracketed together. As thiagotiberio says, that would really help the conductor (and composer!) know who is playing which instrument.