After a fair bit of tinkering, SMBIOS iMac19,1 works perfectly as confirmed by Hackintool (VDA Decoder) and VideoProc with Platform ID 0x3E980003 and Device ID 0x3E98.
If you're on Macmini8,1, it may be necessary to contemplate the change to iMac19,1. This means deauthorizing existing software licenses (as much as possible), signing out of iCloud, then changing SMBIOS to iMac19,1 (which provides new serial numbers), and copying the new Board Serial Number from SMBIOS and pasting it into MLB in RtVariables.
After a reboot, software and plug-ins may need to be relicensed.
Before doing this, make a full bootable backup of the existing system. The procedure is now in the main guide, just under Going the Extra Mile.