Hardware: 15" MBP 2019 - Radeon Pro Vega 20
Software: Boot Camp Unified Driver R3 for Windows 10 (https://drivers.amd.com/drivers/unified_r3_19.30.01.33_whql_191121a-349047c.zip )
Displays: Built-in retina display, External displayport Packed Pixels (x2) on USB-C adapters
Windows recognises all three displays.
AMD settings recognises all three displays
Eyefinity only recognises the external Packed Pixels displays. It can make a single spanned display out of these two, but the built-in retina display is still a separate desktop.
See attached image showing Windows display settings with all three displays, and Eyefinity only detecting two.
Just for reference: Custom Adrenaline 2020 drivers from bootcampdrivers.com are worse - it also only detects the external displays, but on the layout page it only has an option for 0x0 layout.
[EDIT] Some earlier versions of the bootcampdrivers.com installer have the same effect as the official AMD drivers.
Eyefinity configurator should detect all three displays so a single desktop spanning all displays can be created.
Any advice gratefully received. Thank you for your time.