IIRC, Advanced processing Heavy oil output was raised to make up for Basic oil processing providing no more Heavy Oil, so the player had enough lubricant to build bots.
But see the (awkward) situation where the player, after researching Construction Robotics, would only craft bots and stop every all other Petroleum Gas consuming assembly :
The Flying Robot Frame recipe consumes, after intermediate crafts, 60 Petroleum Gas and 15 Heavy Oil. So, as 15/60 < 25/55, Heavy Oil will back up and need cracking. If the player crafts anything that requires PG -




Why it's bad IMO :
- HO cracking setups need to be like twice bigger, without an alternative, smart solution (LO has SF)
- Coal liquefaction recipe loses one of its great interest (HO production)
(no word about blue belts, as they belong to Production science which offers the Coal Liquefaction recipe)