Yes, actions at a single WP are limited to 15. No idea if that is something to do with the DJI SDKs or an issue within the litchi programming itself. While it would be nice to just have a WP pano using the previosly set up parameters, I suspect that the different modes are a bit compartmentalized and trying to switch between them during a mission creates some issues that litchi chose to not have to deal with.
Take 7 photos at Waypoint A. Fly to Waypoint B (I use a waypoint straight above Waypoint A) and adjust camera tilt for next row of photos. Return to Waypoint A and take second row of photos. Repeat for third row if desired.