Enhancement request to start custom slide show from commandline. Builds upon existing --show[=slide_number] option, related to request to export and print slides selected by custom slide show.
and related is also to exit after slideshow ;) a parameter might be added to the macro given there : -> https://ask.libreoffice.org/t/exit-impress-at-end-of-slideshow/67069/2 along with oController.gotoSlideIndex(sStart)