Disabling screensaver doesn't work but I have come up with an alternative I hope.
the command
defaults -currentHost write com.apple.screensaver idleTime -int 28800
I'm hoping will set the screensaver to come on after 8 hours, haven't had 8 hours to test it yet or test what maximum integer can be inserted, or if this needs to be re-applied at startup.
Anyone with any thoughts?