As far as I can tell, a corporation is already not treated as a literal person, only it has some of the same rights. Simplest example, a corporation can't run for a public office. What do you suggest should be changed, no 1A for a corporation?
Yes, corporations are not people, and do not get rights, period. They're legal fictions that get privileges that we the people grant them.
If you want to represent yourself commercially as a person, your rights as a person can be extended to that legal fiction.
If you want legal fiction that you can dump when it's convenient and isn't tied to you as a person, then that legal fiction gets no rights and only certain privileges.
> In 1906, the Supreme Court of the United States ruled in United States v. Detroit Timber & Lumber Co. that headnotes have no legal standing and therefore do not set precedent.