PUP don´t need a crappy WS just for blue !!. Let SP trigger blue !! too and the problem (?) is solved.
If PUP ever get access to AF to trigger blue !! than that doesn´t mean ppl will invite a PUP just for that. A MNK still beats a PUP cuz they can use all 3 blunt weapons and have access to almost all (blunt) blue trigger ws.