Not at all! Would you mind testing this on your system before I make the PR?
Might as well double the sample size 
I don’t have a DP card but if you do, please test that as well.
First to determine which expansion port has the HDMI or DP:
grep -i hdmi /sys/bus/usb/devices/?-?/product
This should give a result such as:
/sys/bus/usb/devices/4-1/product:HDMI Expansion Card
Then enable autosuspend by substituting the above #-# into:
$ echo 'auto' | sudo tee /sys/bus/usb/devices/4-1/power/control
Personally, this is something I would probably add to /etc/rc.local, however I could see the benefit of including it in systemd if the application is wide enough.
Thx!