Thing about bows is that nobody uses them due to drawback, which is slowing you down while drawing the bow. Whereas for the crossbow to be OP you need 0.5/0.25 draw speed, this is where crossbow and materials like Signalium are overpowered, 1st - crossbows do not have a single drawback, 2nd - Signalium offers 0.25 draw speed right off the bat.
Same problem is with Enderium for tools/weapons. It outshines everything by a huge margin. Imo, these two materials should be disabled or heavily "balanced" (nerfed).