from what I am reading the problem is 2 types of lead plates that alternate every other plate
one plate is PB = Lead
the other is PBO2 = lead oxide - the off color plate that chars up does not melt so well
The Dross from battery lead is toxic vapors are toxic But you will get lead in the end that if you Flux will purify



My feeling is if lead ever gets very expensive per pound - all of a sudden it will be worth it . as of now it's on the edge .
I guess if you live in suburbia around other people you really should not be messing with any lead melting especially batteries