DSSR has a cool mosaic module that automatically captures videos for making lunar and solar mosaics. Part of this module is a mosaic preview image that shows the progress of the capture process. This was a bit hit and miss in older versions but I just tried out version 4.7 and I think I have finally got it.
Note that my mount is very roughly aligned so I set the mosaic size to 0.8×1.0 degrees to make sure I got the Moon. First up was a mosaic with the scope west of the pier. This took 22min with each video at 10sec and the mosaic started in the top right tile. The blue tiles are sky which DSSR automatically skips using the Exposures module.
Next up I did a meridian flip and tried again. This time the mosaic started in the bottom left corner and I adjusted the Invert Row/Col checkboxes accordingly. The green tiles were not shot because I stopped the mosaic manually.
Hopefully, you should now be able to shoot mosaics and use the preview to check that you have captured all tiles.