Yes, Jesus frequently broke taboos, even saying that often 'the traditions of men are not of GOD.' And Yes, I'm convinced that Jesus spoke YHWH out loud, because the scripture is very clear that JESUS taught the Name YHWH to those whom He was told to. And YES when you READ Jesus Saying "I AM" in the Neew covenant JESUS knows HE is offending the religious leaders and their tradition of not pronouncing the Name.
(Now, we don't really know how YHWH is actually pronounced...today, the closest is probably Yahweh, and definitely NOT Jehovah, because there was no J in the alphabet of Greek or Hebrew, and it was not invented until (1478–1550) when it was explicitly used to distinguish I and J as representing separate sounds.
This is the one (technical law) that was cited to hang JESUS on the cross, (for blaspheme (literally this means HE spoke the sacred name), as well as considering Himself equal with YHWH (which He was). 'If you knew the Father, you would know Me..'
ELOHIM never said NOT to use HIS personal Name YHWH.
IN FACT GOD/ELOHIM said to KEEP His Name YHWH Holy, as a memorial for all time Exodus 3:14,15.
This is the same clear message that Jesus taught: "Our Father in Heaven, Hallowed be YOUR NAME..." JESUS KNEW the power of the Name of GOD, KNEW the tradition of the teachers of the law, and did everything HE could do reestablish the power of the Name, shining the light squarely on the Rabbis tradition which had been ongoing from about 350bc, the process to remove GOD's Name YHWH from all scriptures, and teachings, this was Man's tradition, and one that Jesus did NOT approve of, and the main one satan fights to this day.
Some of what is missing here is a basic understanding of what you are asking. This is not a simple subject and can take years of research to connect all the dots, and it is still a mystery. The subject of the Name of GOD:
YHWH has been studied by kings and priests, Rabbis and Pastors, Academics, Philosophers, for thousands of years... it's as simple as the Name of GOD, as complex as the Name of GOD, hated by Satan above all else, and received by YAH Saves = Yeshua = Jesus. The Name of YHWH is in the name of JESUS. But this is a revelation that many still fight even in the Church.
JESUS Yehshua didn't actually say: "I AM," this is the English translation from the written GREEK New Covenant, which was translated from vocalized Aramaic.... ALL of which would be referring back to the old Covenant written in ancient (Paleo) Hebrew @ Exodus 3:14. Did I lose you there? ;-)
[Someday maybe we'll uncover (like the dead sea scrolls) ancient Hebrew versions of the second covenant, but for now all we have is the GREEK translation, taken from vocalized Aramaic, which was said earlier, was the common language of the Jews at the time of Jesus era.]
So here's the answer as simply as I can make it.
YES. Jesus was in fact stating a shortened version of the Name of GOD "HWH".. He would have been referencing Exodus:
Ehyah Asher Ehyah, (without vowels it was written as HYH or ancient version: HWH SHR HWH.)
YES, this is YHWH saying first Person: "I AM," which is a very Hebrew way of saying I EXIST, or I BREATHE. FISRT PERSON MEANS THAT WHEN JESUS SAID HWH HE WAS CLAIMING TO BE GOD, MOST NEVER CATCH THIS POINT, AND IT IS HUGE. THIS IS WHY THE TEACHERS WERE SO UPSET AT HIM FOR CLAIMING TO BE GOD. HE CLAIMED TO BE GOD BY USING THE NAME OF GOD IN THE FIRST PERSON. JESUS WAS NOT MEARLY REFERRING TO THE SACRED NAME IN THE THIRD PERSON. It's what HE SAID TO MOSES... this is why the teachers were furious enough to throw stones at Jesus or hang Him.
Extremely INTERESTING that the New Covenant JESUS uses this as you point out: HE BREATHED ON THEM.... YET another key clue to the BREATH of GOD and the Name of GOD intertwined. BUT JESUS DID NOT USE THE FULL YHWH Tetragrammaton with the YOD at the beginning YHWH. Jesus uses I AM "HWH" a LOT by the way throughout scripture, (now you'll begin to notice this over and over)...THESE are all clues to WHO JESUS is, and He clearly did this to show His Power in wielding the Name of GOD, because it was HIS name, and HE wanted everyone to Know His Name and begin calling worshiping HIS NAME again. Erasing GOD or making YHWH vain was a violation of the 3rd commandment or statement.
"Every knee will bow and every tongue will confess that JESUS is YHWH."
I hope this truly helps us all desire to know GOD, by first knowing HIS Name: HWH SHR HWH, YH, and YHWH. To grasp the concept of Erasing GOD.