There are many impracticalities involved.
You say that the word "person" as used in the Constitution refers both to a statutory and a biological person. That it must refer to a statutory person is self evident. That it also refers to a biological person, and was understood and intended to appears to be purely speculation. Every available test I can see that would clarify it fails to produce any evidence that was the original intent and understanding.
There is no basis I can see for a claim that what you are proposing is an exercise in an "original intent" application of the Constitution. It is an innovation - an new interpretation and application. It will have unintended consequences. If "personhood" begins at conception rather than birth, every application of the law that makes reference to that age of a person is subject to challenge.
Many other questions will be asked, from all quarters. Current technology allows us to freeze fertilized eggs almost indefinitely. If they are kept for many years, thawed out implanted, will the person be born already eligible to vote, or collect retirement benefits? While it was impractical to count them then, we do have the technology to do it now. A state could have a facility for creating and storing frozen, fertilized human eggs. The could conceivably stockpile millions of them in a relatively small space. Could the state then use this new interpretation to claim that since they are persons, they should be counted as part of the state's population, and the state then entitled to additional representatives in Congress based on additional population?
There are probably a lot more questions and potential problems this would provoke, and it doesn't appear that you've made any attempt to consider what all the consequences are going to be or are pepared to have answers to the questions.
Forcing a re-interpretation of what the word "person" means in the Constitution will cascade to a potential re-interpretation of every law already on the books that's derived from those parts of the Constitution that make reference to a "person". It would be struck down in courts just for the potential chaos it will cause figuring out how it could affect existing law.
The proper way to do this is with an amendment.
Well, we already know the consequences of your position.
I could show you photos if you'd like.
You first. Amend away the word "posterity" in the statement of purpose.
pos·ter·i·ty/päˈsteritē/
Noun:
All future generations.
Synonyms:
progeny - issue - offspring"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America."