show next dashboard after: x seconds

If you didn't know, you can use the slideshow option to cycle thru a list of dashboards. It uses a fixed time for all the dashboards (so can't be 30s then 15s then 15s, but a fix 15s or 30s per dashboard works. I guess you can cheat and setup 15s cycle then have two identical dashboards to make it look like it's shown for 30sec. Slideshow doesn't seem to let you pick the same dashboard twice.