I have soft released Plone 4.3.20. Please give it a try and let me know if there are any critical issues: https://dist.plone.org/release/4.3.20-pending/versions.cfg.
For those who haven't run across soft-releases before, this is the last step before the final release. Because things haven't been finalized yet, some packages may change between now and the release. It is not recommended to use soft-releases in production.
This will be the last ever release in the Plone 4.3 series! I feel oddly moved when I write this. The first 4.3 release was on 6 April 2013. Seven years ago. It feels strange to let this release go. But it is time to move on. It has been a great release series! Thanks a lot to everyone who helped shape 4.3 and who helped maintain it for all those years. We love you all!
I have a release checklist. Feel free to link possible breaking bugs there, or add a comment below.