I was contacted by Sony Australia yesterday after I requested information regarding Sony's intention to support 4k 30hz. I have copied the response below.
"We provide technical support for the PlayStation Network and consoles, and therefore we are unable to assist you with TV specific enquiries and would advise you to contact the manufacturer directly.
The PlayStation 4 Pro only outputs at 60hz however it can down grade due to application specifications down to 30hz. Due to the fact that the consoles start up and home screen is displayed at 60hz we would be unable to assist further with this issue and advise as stated above to contact to your TV manufacture"
I have been getting pretty disappointed with Sony over the past week. This is a major issue for a lot of people and they are just ignoring it completely. The fact that the 4.6 update did nothing to address the issue is a major problem. If you advertise a product as supporting 4K then it damn well better support ALL versions of 4K.