Make / Model of motherboard - Gigabyte Z370 Aorus Ultra Gaming WIFI
CPU - i7-9700K
OpenCore Version - 0.6.9
dGPU - AMD Radeon RX 580
Does sleep/wake work? - Yes
Does EFI support OpenIntelWireless drivers? No
Does restart/shutdown work? - Yes
Does FaceTime and Messages work? - Yes
Does WiFi and...
What I did was :
Create the custom icons (based on the type of SSD/NVMe I have) using Photoshop.
I used Image2Icon App to convert the .PNG file to .ICNS file. Actually, you can use OC's icnspack terminal command to convert the PNG to ICNS. That command is in OC's Utility folder.
adding boot chime is fairly easy just make sure u got the chime in your audio folder in your EFI and yes you can change your icons as long as the new ones meets the dimensions.Check this link if you want some prebuilt icons https://github.com/blackosx/OpenCanopyIcons