When PFL is in additive mode, and you have prefade enabled on multiple channels on different layers, a single PAFL clear or cancel would save you having to search all the layers to find that one elusive channel - the Yamaha LS9 has a hard button for this, and it is very useful!
this function is implemented, according to the manual…
Yes, PAFL Clear is an available function that can be assigned to the softkeys.