Windows move to secondary display after waking from power save mode

Try DFP-0

Also, you are missing this last lines in your conf

You only need to add to the modules if you enable early KMS, and is already explained

Now, with the latest mkinitcpio the entries are all between ( ) and not " " but still is not a big issue, because will work with both …

Well, if the LG is initiating slower than the Benq and your Samsung, then that might be an explanation, but i’m not 100% sure.