Loop an Entire Playlist

We have a continuous announcement slide loop with around a dozen slides in it each week that last 15 for minutes right before our church gatherings and then also use it in the atrium as digital signage post gatherings.

We typically leave each of the slides up for around 10 seconds at a time and then we want it to change to the next slide. So after the 12th slide has been up for 10 seconds, I would like it to loop back to the 1st slide and continue looping forever until we stop it. My workaround solution has been to create a 120 second video with each of the dozen slides up for 10 seconds at a time. I then export and upload that 120 second video to Playlister. I am able to Loop that single 120 second video element and that is my workaround for an announcement slide loop.

The Problem is that almost each week some of the announcement slides change as new slides are added and old out of date slides are removed, and that means I need to re-export a new video each time I need to change anything in the slide loop. 

Ideally, I would like to have those 12 individual slides in a Playlist with 10 second duration's and then have the whole Playlist Loop repeatedly. That would allow me to just add or remove individual slides without needing to export a new video each time anything changes.

Also another idea I have to solve this problem is would it be possible to put Playlist "A" as a Media asset inside of Playlist "B"? Then I would only have to change a single slide within Playlist "A" and have Playlist "A" as Media Looping within Playlist "B"

We currently have a workaround solution, but I think it could be more efficient if features could be added to either Loop an entire Playlist or put one Playlist inside of a different Playlist. Thank You!