I'm not sure if you will get a consensus on the lead additive question, but I'm fairly sure the majority don't bother, I don't.....
I've not seen good evidence lead prevents pocketing on A10,s but that's not surprising as it would be rather difficult to prove one way or he other.
I've a cast iron b31 cylinder head in my shed, badly pocketed and its not been used for so long it would not have seen unleaded fuel, so leaded fuel did not prevent pocketing on that head, but that's hardly conclusive evidence it does not work!
If my bike had an ally head ...it doesn't....I would opt for valve seats that did not need lead in the fuel.