not sure how much help I can offer, but I had a similar issue at one time trying to stop XFCE from starting any screensavers and also from doing "screen blanking"
I do not remember off hand what I did, except that it required adding a line to my .xinitrc file
There is some command or setting that you can add to turn off any and all screen blanking, but I cannot for the life of me remember what it was called... there might be some old messages on here that I posted back then asking about it, and perhaps one of those might give more detail.
I'll see if I can locate any of those posts.
EDIT: sorry, but I can't find anything that I posted about the issue in earlier threads. I also tried looking to see if I had old copies of my .xinitrc from back then, but evidently I deleted them all