Finishing on a full burn, is not leaving it to smoulder. Vents opened up, intense burn to leave only fine ash.
Soft/hard mix of firewood is best for the reasons nn mentions. Kiln dried isn’t worth the premium, unless you plan to keep it in your airing cupboard, it will just pull the moisture in again, osmosis, equilibrium and science and stuff innit.
We mostly run the firewood processor at 250-300mm as that fits the majority of stoves and we know which customers have stoves that will take the bigger bits that slip through, stoves that require small logs are a pain, not enough sheds to dedicate one to the few people that have midget stoves.
Some species split easier green, others when seasoned, some hardwoods are no good after 18 months (horse chestnut), some softwoods are hard to cut and split once like Sitka spruce once dry. Many variables, a good source is most important for decent dry stuff, not last weeks hedge cuttings.