How does Yandex perceive http2?

Question

Search Engine Optimization

Yandex answers questions about how he perceives http2, only with a couple of notes from one of their blogs from 2016, which says that he is not friends with him, his bot should be directed to http1.1. But now 2018 has come not so long ago, but I didn’t find any materials at least dated 2017 where it would be discussed that http2 Yashka digests.
Do you need to transfer his bots to http1.1 or not?

Answer 1

A properly configured HTTP/2 web server should also be able to handle HTTP/1.1 in case the client does not support the newer protocol. This facilitates the transition between incompatible protocols.

14.42 Upgrade
...

https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
Poorly searched / read

firstlena.pershina July 14, 2016, 19:14
Our robot is already quite able to process the http2 protocol, there will be no problems. But the most common problem that is encountered is returning the Upgrade HTTP header when the client does not require it. According to the RFC (14.42 Upgrade), if the client requests an Upgrade header, then the server MUST NOT return it. That is, you can enable http2 on the server, but you must make sure that Upgrade will not be returned for all requests.

https://yandex.ru/blog/search/use-http2-p...

Answer 2

Works fine with HTTP/2.

Answer 3

It works fine, all the same, you have two protocols working, so what's the difference in essence