I hope the majority of the JUCE team is now finally working on one of the main promised features of JUCE 4: The DSP module. This must be your top priority now, right?
Honestly, if you now start adding JUCE 5 exclusives to the development branch you just make it harder for yourself to create a version 4.3.x with that DSP module included but without those J5 features. Or does it just mean that the DSP module is now finally off JUCE 4?
Why not put this mostly finished (since Nov 2015) DSP module on the development branch right now and get some feedback from the community?
Some context:
A selling point for JUCE 4:
“Coming soon, the DSP module is a compilation of signal processing utilities grouped into one library” (404 - Missing Page - JUCE, after ADC 2015)