It certainly is not "irrelevant" to say Abaddon is Satan when Revelation clearly says:
Rev 20:3 And he laid hold on the dragon, that old serpent,
which is the Devil, and Satan, and bound him a thousand years, And
cast him into the bottomless pit, and shut him up, and set a seal upon him, that he should deceive the nations no more, till the thousand years should be fulfilled: and after that he must be loosed a little season.
Rev 9:11 And they had a king over them, [which is]
the angel of the bottomless pit, whose name in the Hebrew tongue [is] Abaddon, but in the Greek tongue hath [his] name Apollyon.
Abaddon is Satan "loosed" from the pit. Abaddon is Satan in the very act of "deceiving the nations". The word "Angel" implies he is
from the pit, and not
in the pit (otherwise how could Satan (also an "angel") be cast back into the bottomless pit in 20:3?). The Commentary quoted overcomplicates the issue.
Job reminds us that Satan also appears as a worldly personality:
Job 1:7 And the LORD said unto Satan, Whence comest thou? Then Satan answered the LORD, and said, From going to and fro in the earth, and from walking up and down in it.
Incidentally the bottomless pit is going to have a slight power struggle issue if the King from the bottomless pit, Satan who will be cast back into the bottomless pit, and the Beast from the bottomless pit are all different. Rev 20:3 already states clearly that the dragon, the serpent, the Devil and Satan are the same. The Beast and the Destroyer are merely further synonyms for the same evil that is already amongst us. Revelation is not history. Revelation is about the here-and-now.
Rev 17:8 The beast that thou sawest was, and is not; and shall ascend out of the bottomless pit, and go into perdition: and they that dwell on the earth shall wonder, whose names were not written in the book of life from the foundation of the world, when they behold
the beast that was, and is not, and yet is.
Personal statements of our faith right here and now confirm the presence of our names in the Book of Life. And the bottomless pit is welcome to a large proportion of our business leaders, politicians, financiers, statesmen, and other such collaborators of Abaddon.