<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>EthernetBuiltIn</key>
<string>Yes</string>
<key>Graphics Mode</key>
<string>2560x1440x32</string>
<key>GenerateCStates</key>
<string>Yes</string>
<key>GeneratePStates</key>
<string>Yes</string>
<key>GraphicsEnabler</key>
<string>No</string>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string>darkwake=0</string>
<key>Legacy Logo</key>
<string>Yes</string>
<key>Timeout</key>
<string>2</string>
<key>UseKernelCache</key>
<string>Yes</string>
<key>device-properties</key>
<string>7f0000000100000001000000730000000200000002010c00d041030a000000000101060000027fff04002c0000004100410050004c002c00690067002d0070006c006100740066006f0072006d002d006900640000000800000005006201140000006800640061002d0067006600780000000d0000006f6e626f6172642d31</string>
</dict>
</plist>
This is for Middleman. As requested earlier(Sometime ago )
Actually both the displays were MiniDP and not Thunderbolt. Sorry for the confusion. But this setting worked for me with 2 minidp displays (dual or mirror mode)