Yes, after boot this command work fine. But from config file works only resolution change.
<quote author="J.T."> I use thinstation and two monitors with extended desktop and have no
problems. In my thinstation.conf file is for example
XRANDR_OPTIONS="--output DVI-I-2 --output DVI-I-1 --left-of DVI-I-2"
For some reason I was having the same issue but when I enable the CUSTOM_CONFIG=ON the monitor settings do work, I don't even know if that's right but it worked for me. I also found that when I try to use dual DisplayPorts it mirrors unless I specifically set XRANDR to do DP1 and DP2 --right-of DP1