I've made our own screensaver routine and function because of this also.
Basically, you need to use the global settings in FTview, set up a screen number read tag and write tag. also set up the backlight intensity tag.
All screens need their own number, don't worry about using the screen goto tag for all screen changes, I just use it to send you back to the screensaver.
Timer condition of no activity between screen changes is what triggers it and after 5 minutes of no screen changes it kicks you back to the screensaver and drops the intensity. The entire screensaver screen is a large Goto button to return you to the Main screen and it resets the timer anytime a screen change is made and returns the intensity back to 100%.
It's not complicated, it could be better, but it works.