I like your approach.
Before reading your article I favored the view that individual rights couldn't attach until the fetus/baby was mature enough to survive outside of the womb (without extraordinary medical intervention). That was based on the view of being alive as an "individual" as a requirment of having individual rights. With that view, if the fetus/baby could survive following a C-section, then it should not be aborted - rights could be said to have attached.
But I was never that satisfied with that approach since the "bright line" as I stated it above rules out taking extraordinary medical attention to get a "premee" through a week or so. And even a toddler still needs non-medical, special help to survive, so the "bright line" of 'survival independent of the womb' isn't very definitive. And if you allow special medical intervention of any sort, then survivability becomes a moving target given that medical technology is always improving and the point at which a fetus could be removed and survive would keep moving closer and closer to conception. Would a 'test-tube baby' be an individual human being with attached rights? That gets absurd.
Using the formation and maturation of the cerebral cortext appears to provides a more objective way to draw a line.
It turns out that the brain stem is mostly mature by the end of the second trimester, which allows the babies, for the first time, to be able to survive outside the womb. And even though the cerebral cortext is in place then, it is still too primitive to function. The functioning begins during the third trimester. It still isn't fully mature and won't be till somewhere late in childhood. But perhaps a 'bright-line' could be found by specifying a kind of functionality. Learning as a capacity, for example, occurs towards the end of the third trimester (an habituated response to external stimuli that is being facilitated by the cerebral cortex - like a learned response to a distinctive, loud sound).
Then the question arises as to whether the rights should attach, under law, based upon a measurement of the individual pregnancy in question, or should the law be written using a specified number of weeks for all pregnancies based upon medical knowledge of normal human embryology.