Differing witnesses to the same Biblical events are going to cite events according to slants of personality and temperament...weighting some words differently or remembering other things others don’t. That they endeavored to write these things down as faithfully as they could remember them was a work between each witness and the Holy Spirit.
You cite Jude which cites a passage from the book of Enoch. Jude was put into canon which in turn puts Enoch or at least parts of it into play as being inspired by the Holy Spirit. A read of Enoch is fascinating because if there is any truth at all in that book then the whole history of the times of Noah need to be re-examined in light of that book as well as the apparent power of fallen angels to change their forms and to literally physically interact with females. I think the meaning of Enoch as well as other things revealed to John and Daniel remain sealed to our knowledge until God says it’s time for us to know them.
The books we have of Enoch seem incomplete as though they were scattered bits and pieces put together from a lost source. There may be yet a lost complete book of Enoch that God isn’t ready for us to have yet. The writer of the letter of Jude was certainly aware of Enoch as would the councils had been aware that put our present canon together.
As for the Holy Spirit....the only thought and sense I get is....”Just wait...when the truth is fully revealed everyone will be totally shocked and amazed at just what has been going on. A human being’s framing imagination would pale at the full reality of Heaven and the person of Jesus Christ and his or her mind will have no reference points to even handle the truth when it is fully revealed”!
In short, prepare to be totally “blown away!”
Or, we could conclude that God saw fit to include in Scripture whatever was necessary for us to know about Enoch.
The problem with extra Biblical revelation is that if it contradicts Scripture, it's wrong. If it doesn't, then it's redundant and therefore not needed.
Honestly, the Bible is long enough as it is. It contains more than enough material to keep anyone busy for a lifetime and then some, studying it and learning about God.
And people want to or seem to feel the need to add MORE?!?!
WHY?
CHAPTER VII. 1. And all the others together with them took unto themselves wives, and each chose for himself one, and they began to go in unto them and to defile themselves with them, and they taught them charms and enchantments, and the cutting of roots, and made them acquainted with plants. 2. And they became pregnant, and they bare great giants, whose height was three thousand ells. - http://www.sacred-texts.com/bib/boe/boe010.htm `
The biblical ell is closely related to the cubit, but two different factors are given in the Bible; Ezekiel's measurements imply that the ell was equal to 1 cubit plus 1 palm (Tefah),[2][3] while elsewhere in the Bible, the ell is equated with 1 cubit exactly. Ezekiel's ell, by which he gave measurements in his guided vision through a future Jerusalem Temple, is thus one sixth larger than the standard ell, for which an explanation seems to be suggested by the Book of Chronicles; the Chronicler writes that Solomon's Temple was built according to "cubits following the first measure",[4] suggesting that over the course of time the original ell was supplanted by a smaller one.[1] It seems not coincidental that the Egyptians also used two different ells, one of which — the royal ell — was a sixth larger than the common ell;[1] this royal measurement was the earlier of the two in Egyptian use, and the one which the Pyramids of the 3rd and 4th Dynasties seem to be measured in integer multiples of.[5] - https://en.wikipedia.org/wiki/Biblical_and_Talmudic_units_of_measurement