Zoro already got ad CoO Ever since Alabasta.
Regular CoO only allow you to feel people's presence, intention, emotion on basic level.
Correct.
Zoro's CoO after fighting Daz Bones allow him to feel inaminate object and thing without presence on top of maintaining that CoO when he is sleeping.
CoO had been taught to Zoro Ever since he was a child.
Its where Zoro got his ability to always be caucious and Can sense danger coming first before anyone else in the crew. This was taught to him in Shimotsuki village as a child because this is important for any Swordman.
I dont think the sleeping observation is a thing since Daz Bones and I dont think he was taught observation as a child.
Haki is something that comes much later in life, takes decades to obtain, on characters that arent main cast set to be teens...
Zoro is simply good at battle instincts and reflexes, CoO came later and enhanced those already good attributes.
After that Zoro has been trying to cut Steel and become stronger but for someone who doesnt have a DF or was a CoA Monster he lacked the power.
Law for Example as a Swordman dont need to feel inanimate object cause his DF allow him to bypass durability and Kinemon use the borning Sword style which should be enough to melt Steel.
It is not power that he lacked and Zoro even asks - what is it that I am lacking?! when he tries to cut Mr1...
What he lacked was haki which is exactly what he got when he cut Daz Bones.
Most people dont know this - Law isnt cutting anything. It is an ability of his DF and it causes no harm, he is detaching things in perfect condition. He chopped up Kinemon and Vergo into pieces without dealing any damage whatsoever to them.
Kinemon knows haki flow, his firefox style isnt melting steel. That fire is too weak to melt things like steel.
Mihawk is a CoA Monster so cutting Steel aren't a problem for him, while Shanks a CoC Monster. This explain why their CoO is also different.
Mihawk has Ranged CoO maxed.
Shanks lack in CoO, so he created CoO counter.
We dont really know their specialties, people only assume that the swordsman who stands atop of all swordsmen is focused on CoA instead of CoC... Shanks' CoO movie feats are considered not canon. Mihawk's "ranged CoO" sounds like something irrelevant considering that he fights at close range.
Zoro lacked in AP pre Time Skip, he doesnt have Ranged CoO maxed out Once he always get Lost but his CoO is so good he Can feel inanimate object.
In his Desperate attempt to cut Steel he unlocked his form of Advanced CoO that only advanced Swordman pocess which allow them to sense inanimate object (Rock, Steels, Weapons).
Only Zoro has so far shown the ability to sense the breath of inanimate objects, nobody else.
This adv CoO has been enlightened further by making him feel Kaido's invisible winds attack and deviate it with his sword and later stop Kaku's Rankyaku inanimate object while sleeping without any worry.
Everyone sensed Kaido's slashes because things like that carry intent and normal CoO picks that up.
Luffy in FMI sensed an axe coming towards Shirahoshi because it carries intent. It was explained by Rayleigh.
Zoro sensed Batman's arrow coming towards Tsuru since it carries intent and so on...
Zoro also was never caught offguars in Rooftop not even by Big Mom or Kaido. He always reach to them cause hi CoO is Always focused.
Yes, Zoro's battle focus is unparalleled.
This Level and type of CoO is the one needed to overcome Shiryu's DF awakening and will be enlightened further when they fight.
When Shiryu clears visuals, normal CoO can pick him up.
When he clears the aura too, only BOAT can maybe pick up the breath of his sword, if he didn't clear the breath of the sword as well.
I dont know if Shiryu can clear the intent his attacks carry.