You keep using the figurative definition of sabbatismos, which allows for "possibilities" but I do believe it has secondary meaning, not with your understanding of it though.
The literal translation of it means the
keeping of the Sabbath, which remains for God's people.
Not sure why you keep ignoring this fact
Strong's Lexicon
sabbatismos: Sabbath rest
Original Word: σαββατισμός
Part of Speech: Noun, Masculine
Transliteration: sabbatismos
Pronunciation: sab-bat-is-mos'
Phonetic Spelling: (sab-bat-is-mos')
Definition: Sabbath rest
Meaning:
a keeping of the Sabbath, a Sabbath rest.
Thayer's Greek Lexicon
STRONGS NT 4520: σαββατισμός
σαββατισμός, σαββατισμου, ὁ (σαββατίζω to keep the sabbath);
1.
a keeping sabbath.
2. the blessed rest from toils and troubles looked for in the age to come by the true worshippers of God and true Christians (R. V. sabbath rest):
Hebrews 4:9. (Plutarch, de superstit. c. 3; ecclesiastical writings.)
The passage in Hebrews 4 really starts in Hebrews 3 and is calling people out of their rebellion to God. The gospel was preached to them, just as it is to us- same gospel Heb 4:1-2. Those who it was preached to in the wilderness did not profit because of their disobedience and could not enter their rest in Canaan.
What did the children of Israel disobey that we are told not to follow in their footsteps?
Eze 20:13
Yet the house of Israel rebelled against Me in the wilderness; they did not walk
in My statutes; they despised My judgments, ‘which,
if a man does, he shall live by them’;
and they greatly defiled My Sabbaths. Then I said I would pour out My fury on them in the wilderness, to consume them.
So following the path you are teaching that Hebrews tells us not to follow is not leading people into their rest that we are told to diligently enter.
Its why the Sabbath-rest and the rest in this verse literally translates into Sabbath-keeping, which remains for God's people.
Because God's people keep God's commandments- His version, not what was altered by man Jesus warned us about. Mat 5:18
Those who enter into Christ rest also cease from their works Heb 4:10 just as God did, on the seventh day Heb 4:4, the seventh day is the Sabbath of the Lord thy God Exo 20:10 there is no Greater Authority than God and one day you will see it, hopefully before its too late Rev 22:11
Its why NT teaching clearly states, the Sabbath rest is according to the commandment, not according to how man has trampled on God's holy and eternal law.
Luke 23:56 Then they returned and prepared spices and fragrant oils. And
they rested on the Sabbath according to the commandment.
I do believe there is a heavenly rest- which means one has come into peace and harmony with God's will.
This is God's will
Psa 40:8
I delight to do Your will, O my God,
And Your law is within my heart.”
Heb 4:10 For this
is the covenant that I will make with the house of Israel after those days, says the Lord:
I will put My laws in their mind and write them on their hearts; and I will be their God, and they shall be My people.
God wrote His will to mankind which He calls His people Israel and we are only grafted in by faith.
God personally wrote His law with His own finger Exo 31:18 He spoke it with His own voice Exo 20:1 He numbered His law by design, so no one would reduce it to an unbiblical number and said they were Ten Commandments Exo 34:28 He added no more to it Deut 5:22 He placed it inside the ark of the covenant Exo 40:20 where the Sabbath commandment is, the only day God named and gave a number and called it My holy day, the holy day of the Lord thy God Isa 58:13 made for mankind because we are made in His image to follow Him, and said to Remember the Sabbath because He knew man would forget. God kept the Sabbath, Jesus kept the Sabbath, His faithful close followers kept the Sabbath, the apostles kept the Sabbath. God blessed the Sabbath and man cannot reverse God's blessing. Num 23:20 Friend, your disagreement appears to be with God, not me.