Not sure if anyone is still watching this thread, but ran into the same issues and they were as elusive as the OP's. Thought my PSU was going bad (10 yrs was a good run), then video card, but after swapping both, the issue persisted. The video card was the only thing I changed on my Z370 board...
I do believe you BOTH misunderstand.
It was stated that their entire lineup would transition within the next couple of years. Sorry, but while the pro models will more than likely be the last to move to ARM, they will move indeed.
To the sleep question - I have not hacked the 9020 for MacOS, speaking from experience turning them into little gaming machines for the family to play VR together across the country on.
To the output question - I find the card defaults to the DVI or HDMI output over the DP's.
Rebuilding my wife's machine to use an i3 8100. Made a 9.1 UniBeast stick just in case. Set the BIOS variables to what I believe to be correct (AHCI SATA mode, VT-D off, CSM attempted both on and off).
Her old install was using the bone stock config + SMBIOS + audio and ethernet kexts...
Was using the same settings I am using on the current build - UEFI and injected via Radeon DeInt - also tried WhateverGreen with and without injecting ATI from the booter.
Regardless, this thread is about the Z77 build, which, for now, seems to be working "okay". Down the road, I will attempt...
Odd twist of fate this morning. Attempted to build wife a new hack out of a Dell 9020 I had lying around. Couldn't get the 570 to initialize right on it.
Rebuilt the components back into her original hack and so far (knock on wood), no issues.
Yeah I saw that... but I have no issues with the keyboard. Additionally, it boots normal after beeping. Possible since I have the keyboard receiver on the front panel, it throws the error during boot. Could be a red herring.
Bit of an oddity on my Wife's hack after upgrading to Mojave.
Installed with UniBeast + MultiBeast 11.
Z77 Asrock Pro4
RX 570 MSI
Broadcom BT+Wifi card to PCI-E 1x (tried multiple).
The issue I am having is that when uploading at all, the system flat out shuts down...