It becomes difficult to reconcile that claim with the rest of your post. You're also unwilling to extend the same liberty you claim to have to others who share in God's redemption.
I'm not among those who claim that the Mosaic covenant Law changed in essence, seeing that Hebrews 7:12 suggests a change in location (or, jurisdiction) as the Greek
metatithēmi is used to declare a 'change' in the Law according to Hebrews 7:12, consistent with the context. See the
Blue Letter Bible for how this same term is used in other passages.
You could also follow on one more verse to v.20 in this same passage, and see that the righteousness the Pharisees and scribes appealed to from the Law isn't sufficient to gain eternal life. The fulfillment of the Law Jesus promised in His statement above is found in His propitiation, completing the demands of the Law in His atonement. That fulfillment demands a sacrifice without spot or blemish, which you and I aren't qualified to perform.
This follows the fallacy that the attributes of the Creator equal the attributes of the Law. God retained mercy to Himself. On the other hand, the Law demands atonement for reconciliation. For fun, take a look at Romans 11:32 in its context:
For God has committed them all to disobedience, that He might have mercy on all.
Unrelated to the content. This doesn't form an argument worth consideration.
And you didn't even ask about what mistranslation I might have been referring to, showing no interest in the point I raised. But since you brought up your exhaustive knowledge of the Word of Hashem, tell me what Jesus was teaching Peter about limited jurisdiction from this passage found in Matthew 17:
24 When they had come to Capernaum, those who received the temple tax came to Peter and said, Does your Teacher not pay the temple tax?
25 He said, Yes.
And when he had come into the house, Jesus anticipated him, saying, What do you think, Simon? From whom do the kings of the earth take customs or taxes, from their sons or from strangers?
26 Peter said to Him, From strangers.
Jesus said to him, Then the sons are free."
Keep in mind the central message of the Gospel of God's adoption as His own children, no longer accounted as children of Israel or children of Gentile descent who were estranged apart from God during the tenure of the Law (see Ephesians 2:11-18).