I am giving the new presenter notebooks in V. 11.3 a try and would like to have full-page background images for individual slides. After some fiddling I managed to do this in the old Slide Show format. What is the recommended way to do this in presenter notebooks? If possible I would like to use a different image for the First (Title) Slide, and/or for individual slides.

For the Slide Show notebooks I used:

Cell[StyleData["Notebook", "SlideShow"], BackgroundAppearance->  FrontEnd`FileName[{"SlideShow"}, <image-name-1>],  GeneratedCell->True,  CellAutoOverwrite->True]

Cell[StyleData["FirstSlide"],  PrivateCellOptions->{ "PagewiseNotebookBaseStyle"->{  BackgroundAppearance -> FrontEnd`FileName[{"SlideShow"}, <image-name-2>]}},  GeneratedCell->True,  CellAutoOverwrite->True]

The images <image-name-1> and <image-name-2> are sitting in C:\Program Files\Wolfram Research\Mathematica\11.3\SystemFiles\FrontEnd\SystemResources\Bitmaps\SlideShow\