Output slides with deeper sections/slides and no text?

[Tim]

I've got a big bookdown project with each book chapter as a separate RMD file.
I was hoping to use the RMD to output slides. Tried all of them and while they worked, I couldn't find how to adjust them to make it work for what I was trying to do:

• ioslides_presentation - HTML presentation with ioslides
• revealjs::revealjs_presentation - HTML presentation with reveal.js
• slidy_presentation - HTML presentation with W3C Slidy
• beamer_presentation - PDF presentation with LaTeX Beamer

They seem to have issues with having slide levels being set to lower than 2. I was hoping to set to 3 or 4.

For example, RevealJS help file says:

slide_level Level of heading to denote individual slides. If slide_level is 2 (the default), a two-dimensional layout will be produced, with level 1 headers building horizontally and level 2 headers building vertically. It is not recommended that you use deeper nesting of section levels with reveal.js.

Also, it would be nice if there was a way to exclude normal text entirely. Just show tables, equations, code chunks, and figures. I suppose a pre-processing step that substituted all 3 and 4 level headings from the RMD to be 2 level in a temp file might be a hack that would work.

They all seem to work great for RMD/QMD made specifically for this but hard to dual purpose the same RMD file.

Any suggestions?