The official reveal.js platform at slides.com also support remote presenting, streamed to any number of viewers. More info and screenshots at https://help.slides.com/knowledgebase/articles/333924-presen...
She was doing phone conferencing for audio at the time.
Worked really well for its purpose and was super simple.
She has since moved to zoom and just does plain screen shares now.
What's your use case out of interest?
Having the slides automatically synced during presentation would require way less bandwidth than screen sharing and thus result in a better experience for both parties.
Would be nice to stream audio directly with the presentation to facilitate things like investor calls without requiring a full conferencing solution