I’m not sure this is the right place for requesting this, but here we go anyway:
I recently wanted to explain the meaning of crescendo hairpins with flared ends in the preface of a score by including a graphical representation of it in the text. Since there is no such symbol in the SMuFL specification, I ended up Frankensteining one by putting together a hairpin with brass technique symbols for lift and fall. Since I suspect that other composers might want to do the same thing, I think it would come in handy having such a pre made symbol ready to use.
All the best!