I just added this to the mythical "next version". There are two separate timers.
I would guess that usually a longer delay for the first flip is desired, so for example you may want pages to start flipping after 5 minutes but then flip every 30 seconds thereafter.
FirstAutoFlipTimer sets the interval for the first flip and AutoFlipTimer sets the interval for the remaining flips. These are both set in seconds. If either timer is disabled or set to zero, then all automatic flips will go by the remaining timer. If both timers are disabled or set to zero then no auto flips will happen. The timers are reset on any mouse movement or any input that would cancel a screensaver.
The timers trigger CMD_NEXTPG rather than BTN_NEXTPG, so button icons or sound effects tied to the actual page button will not be triggered.
I really hope to have the new version up this weekend, but I know I said that last weekend. I'm trying, folks!
--Chris