VBoxManage.exe setextradata "VM Name" "VBoxInternal/Devices/efi/0/Config/DmiBoardProduct" "Iloveapple"
VBoxManage.exe setextradata "VM Name" "VBoxInternal/Devices/efi/0/Config/DmiSystemProduct" "iMac19,1"
VBoxManage.exe setextradata "VM Name" "VBoxInternal/Devices/efi/0/Config/DmiSystemVersion" "1.0"
VBoxManage.exe setextradata "VM Name" "VBoxInternal/Devices/smc/0/Config/DeviceKey" "ourhardworkbythesewordsguardedpleasedontsteal(c)AppleComputerInc"
VBoxManage.exe setextradata "VM Name" "VBoxInternal/Devices/smc/0/Config/GetKeyFromRealSMC" 1
VBoxManage.exe setextradata "VM Name" "VBoxInternal2/EfiGraphicsResolution" 1600*900
Additional / Differing Commands
VirtualBox 5.x / 6.x (Intel processors)
VBoxManage.exe modifyvm "VM Name" --cpuidset 00000001 000106e5 00100800 0098e3fd bfebfbff
VirtualBox 4.x (Intel processors)
VBoxManage.exe modifyvm "VM Name" --cpuidset 00000001 000306a9 04100800 7fbae3ff bfebfbff
VBoxManage.exe setextradata "VM Name" "VBoxInternal/Devices/efi/0/Config/DmiBoardProduct" "Mac-2BD1B31983FE1663"
VBoxManage.exe setextradata "VM Name" "VBoxInternal/Devices/efi/0/Config/DmiSystemProduct" "MacBookPro11,3"
VBoxManage.exe modifyvm "VM Name" --cpuidset 00000001 000106e5 00100800 0098e3fd bfebfbff
VBoxManage.exe modifyvm "VM Name" --cpu-profile "Intel Core i7-6700K"