"It is illegal to clone (make physical copies of) or ST-clone (make mental copies of) any Star Army citizen/plebeian/soldier that you do not own without their consent (Proposal 39, Item 2)."
"2. Yamataian citizens have a right to back up their minds every three months. Citizens should write a will dictating how and when they should be revived. The Yamatai Star Empire (or agencies thereof) shall keep backup centers in all cities with a population of 5,000 or more."
So we have two statements here - one that says straight up when a citizen can ST themselves for safety and another that implies that ST's can be done on plebeians. Now this seems weird until you understand we are not talking about Elysian Plebeians but the legal entity in Yamatai known as Plebeians which is defined as:
"4. A citizen is an official member of the Empire, while a plebeian is not. Plebeians include willingly conquered members of other nations, and unregistered Geshrin (Proposal 3, Item 4). Those once owned by Citizens or Corporations owned by Citizens now hold Plebeian status."
Also plebeian status is applied to certain allied nations through:
"5. The Yamatai Star Empire will designate plebeian rights to citizens of any nation with whom such an agreement has been previously made in treaty."
Next we get to his statement: "1. Every non-citizen has the right to their own thoughts, mind, and exclusive control of any backup copies thereof. (Proposal 3, Item 8; revised by Ketsurui Hanako-Taisa)."
Which highly connotates that non-citizens (and I would say almost certainly plebeians) have access to ST technology. It is free and a right of proper citizens (which by the way is defined as: "3. Citizenship to the YSE is not obtainable by birth alone. To become a citizen, those applying for citizenship must participate in an interview, download a civic information packet, and take a written or oral test. If the applicant lacks a digitized brain, they will receive study materials, and take the same test after a designated amount of time to study.", with a couple exemptions) but I would assume that others could pay for it as a civic service if they pass a background check or have legal residency in a YSE locale like you would be able to pay for a medical procedure in the modern day.
To addendum my post to things outside Yamatai origin: Freespacers definitely know how to digitize a brain and with them as fractured as they are you could probably get that done for payment on the down-low real easy. At that point you just slam yourself into a robot body of some sort - or even one of the synthdroids like the Mimicoms sold by Origin or various other approximations of human options that can be bought.
In fact, we do without doubt have the technology level to make a cyberbrain after you've made a digitized version of yourself and could probably implant it into a body that wasn't originally yours. The 'space brain into a synthetic body is definitely grey area legally and doing so on the body of a living person that wasn't your clone is definitely illegal. Cloning alone is a pretty watched/restricted sector.
So, yes actual ST's are restricted. If you know the right people or have enough money to play in a world where you can pay to do the same - can you basically have a facsimile of ST technology? Yes.