Concerning the previous site and this site ...
https://kjvcompare.com/genesis-27-39 while noting the kjvparallelbible.com only compares NT text.
This kjvcompare site positions the KJV with some other translations --but each in their standard wording. The comparison for Gen 27:39 shows a problem of the KJV rather than a positive sense.
KJB
And Isaac his father answered and said unto him, Behold, thy dwelling
shall be the fatness of the earth, and
of the dew of heaven from above;
NASB
Then his father Isaac answered and said to him, “Behold,
away from the fertility of the earth shall be your dwelling, And
away from the dew of heaven from above.
So the website claims:
In the KJB, Isaac blessed Esau. But in modern translations, he curses him, contradicting the Holy Ghost in Hebrews 11:20, which reads:
By faith Isaac blessed Jacob and Esau concerning things to come
= = = =
The commentary instead notes:
Behold,” it states, “from the fat fields of the earth will thy dwelling be, and from the dew of heaven from above.” By a play upon the words Isaac uses the same expression as in v. 28, “from the fat fields of the earth, and from the dew,” but in the opposite sense, מִן being partitive there, and privative here, “from = away from.” The context requires that the words should be taken thus, and not in the sense of “thy dwelling shall partake of the fat of the earth and the dew of heaven” (Vulg., Luth., etc.).
Carl Friedrich Keil and Franz Delitzsch, Commentary on the Old Testament, vol. 1 (1996), 178.
This would indicate that the KJV translation must be read with caution lest the reverse meaning be perceived. Esau ended up in an inhospitable land.
The idea expressed in the words, therefore, was that the dwelling-place of Esau would be the very opposite of the land of Canaan, viz., an unfruitful land. This is generally the condition of the mountainous country of Edom, which, although not without its fertile slopes and valleys, especially in the eastern portion (cf. Robinson, Pal. ii. p. 552), is thoroughly waste and barren in the western; so that Seetzen says it consists of “the most desolate and barren mountains probably in the world.
Carl Friedrich Keil and Franz Delitzsch, Commentary on the Old Testament, vol. 1 (Peabody, MA: Hendrickson, 1996), 178.
A specific distinction between the blessing to Jacob and the curse of Esau can be observed in the verses. God is the source of blessing in the blessing of Jacob
Gen 37:28 (NKJV) Therefore may God give you
Of the dew of heaven, Of the fatness of the earth, And plenty of grain and wine.
and for Esau
Gen 37:39 (NKJV) . . . “Behold, your dwelling shall be of the fatness of the earth, And of the dew of heaven from above.
One thing that the KJV is missing is that "Of" and can apparently be "from." The ambiguity would then be between "from" as a benefit or "away from" as a curse. Hopefully I helped some rather than adding more confusion. The consequence then is that the modern translations (even if from the Textus Receptus) clarify the different implications between the blessing and the curse.