> OK. I am available to help with testing, especially if there are changes
> where you think there may be backwards incompatibility issues such as #3865.
> I have quite a few doc sets with custom extensions that I can run tests
> against. I will try to watch for beta releases, but if you would like to
> contact me directly that is OK, too.
Thank you for your offer. That would be nice :-)
According to our deprecation policy, we will announce and warn about
deprecation during a major version at least.
So I can promise you not break compatibility suddenly if you use
public Sphinx API.
(Of course, internal structure might be changed.)
https://github.com/sphinx-doc/sphinx/blame/master/CONTRIBUTING.rst#L313
Thanks,
Takeshi KOMIYA