I got curious about what the Bolsheviks would have done so I searched.

Interestingly enough, the Bolsheviks seemed to have went for no fixed or constant age of consent; instead, they used the presence of puberty as a primary factor for the age of consent. Courts would use medical testing to determine if a person was going through puberty.

In the 1922 RSFSR Criminal code of article 166 and 167:^[https://docs.cntd.ru/document/901757375]

4. Преступления в области половых отношений

166. Половое сношение с лицами, не достигшими половой зрелости, карается - лишением свободы на срок не ниже трех лет со строгой изоляцией.

167. Половое сношение с лицами, не достигшими половой зрелости, сопряженное с растлением, или удовлетворение половой страсти в извращенных формах, карается

4. Sexual offences

166. Sexual intercourse with persons who have not reached puberty is punishable - by deprivation of liberty for a term not less than three years with strict isolation.

167. Sexual intercourse with persons who have not reached puberty зрелос, involving corruption, or the satisfaction of sexual passion in perverted forms, is punishable - by deprivation of liberty for a term not less than five years.

Same for the 1926 RSFSR Criminal code:

151. Sexual intercourse with persons who have not reached puberty, involving corruption or satisfaction of sexual passion in perverted forms, - imprisonment for a term of up to eight years.

Sexual intercourse with persons who have not reached puberty, committed without the specified aggravating signs, - imprisonment for a term of up to three years.

152. Debauchery of minors or minors committed by means of debauched acts against them, - imprisonment for a term of up to five years.

153. Sexual intercourse involving physical violence, threats, intimidation or using the victim's helpless state by deception (rape) - […]

154. Entering into marriage with a person who has not reached the age of marriage, - imprisonment for a term of up to two years. Entering into a marriage with a person who has not reached puberty , or forcing him to enter into such a marriage - the measures provided for in Article 151 of this Code .

So, for example,

• If there was a 16 year old teenager and they had not gone through puberty, they would technically be considered a minor and thus lack age of consent.
• If a 15 year old teenager had initiated puberty and there was no coercion, they would have consent.

Of course this is for the RSFSR; I don't know what the other soviet republics did.

Surviving socialist states

The current surviving socialist states seem to have stuck to the more common fixed age of consent concept:

Age in years:

• China - 14
• Laos - 15
• DPRK - 15 (from 0 years, I think)
• Cuba - 16
• Vietnam - 18

I thought that was implied through the general term damage, that's why I used the general term damage and not just physical. Sorry if it came off that way.

(Technically, all damage (physical, emotion, neurological, etc.) is physical as it affects the human body, but that shouldn't and hopefully doesn't downplay their effects and importance of recognition.)

Because someone using their power dynamic to coerce a minor into sex isn’t sexual abuse to some people, while it is to me, for example.

That is sexual abuse to me.

To attempt answering your question, I dont think its solely a matter of sexual development of the body. Mental development is much more important, especially the ability to manage human relationships and set boundaries.

I didnt think about brain development until now. Yes, that is important.

Age of consent is also not simply a binary question of yes or no

Yes. through dialectical materialism, sexual coercion can't be simplified into merely use of physical force; there is also economic coercion (through capital), and they all influence consent.

One approach I know about is that relationships between young teenagers are only legal up to an age difference of 2 years or so, not with adults.

OK.

It also makes sense that parents should be able to decide if their child can enter in a relationship with a specific person, after all they know their child best.

It's also said that the child knows best; and I think that children should learn what makes for a good relationship (no damage of all types).

I have issues with rape and abuse; of course I want to be and am against that.

Yeah, maybe I should have worded that more clearly to say "sexual abuse" is still bad.

Never said prepubescent sex was good. It's still bad because it damages the child.

You’re assuming age of consent is about puberty, reproduction, but age of consent is about being intellectually capable of understanding and having responsibility for actions, which isn’t something you can measure in a physical sense.

1. Intellectual knowledge in a person would have to be physical though, otherwise it wouldn't affect the brain (and they wouldn't learn anything).
2. Simple solution then: Initiate sex education at all school levels and multiple times.

“the conclusion of sexual development allows a person to have sex without sustaining damage” this is baseless and incorrect

How is it baseless and incorrect? Without puberty, humans would never become able to sexually reproduce safely and also develop into adults.

fucking creepy as shit, tbh

What's creepy about saying that ending puberty allows a person (or adult in that case) to perform sex safely (without sustaining damage)?