Can you now boot without nomodeset?
Here I had no issue with the 4.3 kernel, no add. kernel options from default supplied needed. I may be able to try again tonight to see if anything has changed over last couple of weeks.
(- the only other difference is my laptop came with a i7 u cpu. I didn't notice nor knew what the u meant, now I do though due to some unfortunate circumstances wasn't able to use the laptop until the 14 day return was over so am stuck with...
Otherwise have you tried removing nomodeset & using this instead as a kernel option?
Code:
i915.preliminary_hw_support=1