I would contact Novak to see.
The conversions you are seeing with a seperate UBEC most likely are mated with a Mamba Max ESC as its only rated to 3S with the internal BEC. when you eliminate using the internal one, you can do 4S with proper cooling (or, adding a nice capacitor to it from what I am hearing)
As for my conversion, I am planning to order the following:
1. Novak 2700 capacitor
2. MBX5 lightweight pivot balls
3. Titanium screw kit upper (maybe)