Being the "God-recognized, God-approved way to procreate", doesn't prove that all other methods of procreation are an abomination.
There is only one way of procreation (onah): marriage/sexual union. Insemination and implantation is not marriage (onah), nor is it a sexual union. The only thing we should be doing is things that are God-recognized and God-approved, otherwise who are we working for? God states several times that the union of man and woman is for fruition of the human race. Creating life in any other way is not recognized by God, and therefore should not be an issue.
Knitting a sweater doesn't mean one is creating a sweater, only forming it of the yarn that already exists / was previously created. Similarly, I believe when God knits a child together, it is clearly describing the stitching together of preexisting DNA. It is not the same as the creation in Genesis.
Knitting a sweater does mean one is creating a sweater, just like molding a pot out of clay is still creating a pot. Just because the substance exists doesn't mean it cannot turn into a new creation. This is the metaphor of the dead human spirit becoming a new creation: the soul exists, even existed, died and then restored by faith in Christ. Creation in the bible is "bara" in Hebrew, which means "to create, to cut down (a wood), to select, to do, to dispatch, to make." So, creation from something is the same as creation in the bible. God just so happens to be able to create something out of nothing.
Of course knitting a child together in the womb is synonymous with what we know as DNA combination and replication, etc. However, if you are genetically engineering DNA, you are playing God. He is the one whose job it is to engineer us. When humans engineer themselves, it is called
Transhumanism, or
H(uman)+, as in "above and beyond the form of human." It is wrong; it exaults the human without incorporating God. It is an example of science superseding faith.
The phrase "in the womb", I believe is there to make it clear that a child is not just a blob of tissue and that abortion is taking a human life. I don't think it is of the supreme importance which you ascribe in disallowing a clone to have an eternal soul that can receive the gift of salvation.
A clone is NOT conceived by marriage (onah), and in most cases is not born of a woman's womb. This is the
first qualification given by Christ for souls to be eligible to enter the Kingdom. A clone is created by man, engineered by man, and implanted by man. God is nowhere in the mix. The minute a scientist starts to tinker with genetics is when s/he pollutes the creation(s) of God. The human creator is the one that damns the clone, not the clone, just like the fallen angels damned their offspring the nephilim by synthetic biology (transubstantiation into a form to mate with humans on earth despite the plan of God to be born of woman.)
Even if a scientist tries to knit DNA with his own hand in forming an embryo, I believe the DNA is still only knit together by God, and the resulting child will have the same breath of life given to mankind by God in the Genesis account.
DNA polymerase substrates are often used in the lab to create elementary DNA polymers. In my biology class, one of our labs was to create our own blob of DNA from cheek cells - growing DNA. With genetic engineering, the DNA can be
told to make arm cells for example instead of, say, cheek cells. So, a scientist can try to knit DNA together
like God, and often times they do "knit" DNA like God. The Designer Children phenomena that occurred in early 2000s was a gross form of genetic engineering, showing ignorance of God. The breath of life is given only by God, through the accepted form of birth. A human creating another human is wrong: case closed. If you want to, feel free to let another imperfect human experiment on your genes.
I think I have opined enough.