Where is the breve anti-accent? Where are square brackets? Why aren't notes in parentheses played softer?

I cannot find the breve anti-accent. It looks like U-shape over the note, and indicates that the note is slightly softer than normal. The "bend" mark in the Articulation sub-menu has a similar appearance, but of course doesn't produce the same affect when Noteflight plays it.

Parentheses around a note are supposed to indicate that the note is significantly softer. However, Noteflight does not play these notes any softer.

I also cannot find brackets. Square brackets around a note are supposed to indicate that the note is much softer.