platform engine : activating a jump while not on a solid?

Hello helpful people of the forum!

Is there any way to activate a jump while not standing on a solid using the platform engine?

I don't mean a double jump.

I have a character hanging under a platform but would like the character to be able to jump out of this state.

Thanks in advance as always for anyone willing to offer suggestions.

Either simulate the jump (it's a platform behavior action) or set its y vector to -self.platform.jumpstrength or some other negative value for a different jump height.