How to set ipv6(6to4) priority higher than ipv4?

Question

Google Chrome

The essence of the problem is that there is a suspicion of a forced "slowdown" of the Internet to some foreign resources.
What I checked - raised 6to4 to hurricane electric, blocked ipv4 traffic and lo and behold, sites with ipv6 support began to work more cheerfully.
But there is one thing, the priority goes like this ipv6 native-> ipv4-> ipv6 tunnel.
The logic here is obvious that if there is a native ipv6, we go through it, but if the address is received through the tunnel, then it is expected to work slower than the ipv4 connection.
But unfortunately in my case this is not the case.
Google does not help, because. everyone is looking for a solution to the opposite question - having native ipv6 they want to lower its priority.

Google for meHelp me good people, otherwise Google will ban me soon, maybe I'm asking him the wrong way? I did not find any necessary handles in chrome://about/ and chrome://flags .

PS I apologize for not specifying in the body of the question. HE according to rfc issues addresses from the prefix 2001:0000/32, this prefix clearly indicates that the address is teredo. The catch is this, tell me how to fix this moment without getting into the source code of the browser.

Answer 1

If you open a tunnel on the router and announce /48 to the local network, then the devices will assume that they are connected to the ipv6 native network.

Answer 2

On my router, a he tunnel was raised to the Netherlands and squid and radvd were also raised there - that is, clients get their subnet in ipv6, and even when accessing the proxy (squid) via ipv4, further requests go via ipv6. That is, when the client types in the Google browser, next to the search bar, nl and a suggestion to change the language are lit, and on YouTube all advertising is in English :)
Yes, the packet sizes are smaller (mtu 1280), pings are larger (50-80ms), the number of hops and the speed strongly depend on the address, for example, in Russia and Europe ipv4 is faster, and if you ping Australia or New Zealand, then the ipv6 route is shorter and the speed is higher (15 megabits over ipv6 versus 6 megabits over ipv4).