We are considering to release v5.2.0 (the first stable version out of branch 5.2) next week, likely on Wednesday, Nov 28, 2018.
It still allows a bit more than a week of testing as well as well time to prepare the online resources for it (documentation, wiki pages, upgrade guidelines, etc…).
If there is any issue you are of and not yet reported to github.com bug tracker, do it as soon as possible to give it a chance to be fixed in time for the next major release.
Thanks for flying Kamailio!