Can anybody tell me if the latest El Capitan betas have allowed the 2015 MacBook to transmit to full 2560x1440 over HDMI? I had updated mine to Public Beta 2 a couple weeks ago and it could only do 1080p, which looked horrendous. Makes no sense to me either as Yosemite is working flawlessly in regard to connecting to an external monitor at 2K resolution.