Ive never really cared but thats just me. Especially if its just a little mold. i dont even purge my bho cause i make so little i dont want to invest the money in a vacuum
But thats against everyone and evertything ive heard. I just take my life in my own hands and dont care about the little amounts of whatever are in there. I use maybe 7-14gs to make bho and thats like once every couple of months. So the amount of butane id be inhaling cant be much, little enough that i dont care to invest.
As for mold ive used an oz of moldy bud (just a little in the middle like you said yours was) and im still livin today. Doesnt mean it didnt hurt me but who knows.