UNET HLAPI How to parent spawned object to something and keep it buffered?

So I want to spawn an object and attach it to another object (set parent)
And client who will join the game some time later, should have this object parented to correct object.
How to achieve that?

If we will use RPC in order to parent object manually after instantiation - new clients will not have this information because RPC is not buffered in UNET.

The only possible solutions which I found was based on some kind of LLAPI magic, super complex and confusing, completely unacceptable for UNET which supposed to be "simple".

So, this is impossible?

I am very surprised that there is no information about this super basic and important task in the manual or on the forums.
Without this feature, UNET is useless for anything except very simple games.

 

Doing this isn't simple because networkidentity components on child objects is not a supported use case.

https://docs.unity3d.com/ScriptReference/Networking.NetworkIdentity.html