Nothing in the byHost fodler starting with com.apple.windowserver. I deleted the plist, rebooted and did the rotation. Attached fresh plist.
OK, just like I thought this procedure resulted "fresh" plist and now it makes sense.
Since you have nothing in ByHost folder modifying this plist should make a trick.
Only program I used was the python script posted also in this thread for fixing the RGB issue (which it initially did).
Hard to say what caused that but your previous plist did not make any sense as it did not have matching UUID for the profile your OS was using, so no wonder it was not working. Also your previous plists had some other weird values for some other things too besides what actually needs to be changed but in this new plist they are ok.
Anyway I marked red what to modify.
Also in case your plist ever shows more that one UUID then just follow the code, it basically gets repeated like this as many times as there are different UUID and then you just edit the part below "LinkDescription". I'm pretty sure there will added something in your plist as soon as you change resolution to something else.
I hope it is readable enough because I could not use code tags.
Please let me know if that worked for you!
<?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>DisplayAnyUserSets</key>
<dict>
<key>Configs</key>
<array>
<array>
<dict>
<key>CurrentInfo</key>
<dict>
<key>Depth</key>
<integer>8</integer>
<key>High</key>
<real>2160</real>
<key>Hz</key>
<real>60</real>
<key>IsLink</key>
<false/>
<key>OriginX</key>
<real>0.0</real>
<key>OriginY</key>
<real>0.0</real>
<key>Rotation</key>
<integer>0</integer>
<key>Scale</key>
<real>1</real>
<key>Wide</key>
<real>3840</real>
</dict>
<key>LinkDescription</key>
<dict>
<key>BitDepth</key>
<integer>8</integer>
<key>EOTF</key>
<integer>0</integer>
<key>PixelEncoding</key>
<integer>0</integer>
<key>Range</key>
<integer>1</integer>
</dict>
<key>Rotation</key>
<real>0.0</real>
<key>UUID</key>
<string>1DDAC0DB-867C-8875-0857-D6964E3302DB</string>
<key>UnmirrorInfo</key>
<dict>
<key>Depth</key>
<integer>8</integer>
<key>High</key>
<real>2160</real>
<key>Hz</key>
<real>60</real>
<key>IsLink</key>
<false/>
<key>OriginX</key>
<real>0.0</real>
<key>OriginY</key>
<real>0.0</real>
<key>Rotation</key>
<integer>0</integer>
<key>Scale</key>
<real>1</real>
<key>Wide</key>
<real>3840</real>
</dict>
</dict>
</array>
</array>
<key>Orientations</key>
<dict>
<key>1DDAC0DB-867C-8875-0857-D6964E3302DB</key>
<integer>0</integer>
</dict>
<key>Underscan</key>
<dict>
<key>1DDAC0DB-867C-8875-0857-D6964E3302DB</key>
<real>1</real>
</dict>
<key>Version</key>
<integer>1</integer>
</dict>
</dict>
</plist>