Hilariously enough I just came by looking for the same exact thing after noticing that crushing > melting was getting starting to get slightly closer to crushing > enriching > melting because of the productivity research.
I'm glad to hear you've already handled it because while a good setup will certainly fill those belts, I'm plugging holes in a steadily sinking spaghetti ship since my robots started stealing my LDS stacks because I set up a recycling chain some attention-spans back and can't track down where it's all going.