@patrakov the IETF seems to work on one issue you mentioned 9in the past:
see here:
maybe a good idea to contribute on the IETF list to get this situation improved?
IPv6 has the Preference bitfield that routers can assign in ND RA. Something more complex?
The thread and the document concern a situation different from what I have at home. Namely, they are talking about multiple routers being present. This is not what I have operational experience with, and thus, my judgment of what is good and what is bad could be wrong.
Therefore, I will refrain from participating in this discussion.
For my network, RFC8475 would be the most appropriate solution.