A long overdue announcement I think, but the last pull requests I will process before compiling and creating an r4 beta to be released is this Friday, April 14th, 2017, Central Daylight Time (GMT-5:00). You might squeak by if you get a PR in by early saturday morning. After that, I have to begin the painstaking process of doing all the little things to prepare for release, and the time from the beta to the actual release can't have any new changes in the master branch. I've got a text file somewhere reminding me what all those little things are....
I may be contacting contributors privately to discuss certain minor aspects of this process, in particular, applying the proper copyrights to new files, under the proper (preferred) names/handles.
So, long story short, if you're a contributor with something worth making it into beta, go ahead and make a PR by Friday so I can merge it before I release the beta.