@rivalpro I wrote a forum post a while back for this type of “slideshow,” with a variable number of slides. You can find it here.
There is one minor tweak that you can do with this method. We’ve added comp switching via a flag in your data (wrapping the comp name in double curly braces) to the latest version of Templater, so instead of swapping with a video asset, you could swap with an empty 2-frame comp that is double the framerate of the containing comp.