I just skimmed over this but your question of turning chunks into ingots to me has an obvious solution?
Just send the chunks into an item barrel that is set to hold coal coke ingots. It will accept any size “metal” and turn it into whatever size you need. Such as blocks, ingots, chunks, nuggets.
EDIT: This also works for dusts.
But not for ores of any quality. I.E, you can’t turn tiny purified X into regular purified X or their crushed/refined counterparts.