Thanks for the suggestion! I think some the syntax rendered here as well, so here are screenshots (apologies!) of what I tried based on what I think your suggestion was, and the knitted output.
So yes, the syntax renders without error! But I'm also not displaying backtick r in front of the chunk_reveal, closed by another backtick.
Here is the screen shot of what I submitted and the result.
Following the recipe you linked to, where knitr::inline_expr usage is shown, should have work:
---
title: "Test inline expr"
output: html_document
---
To use `chunk_reveal("walrus", title = "## Walrus operator")` inline, you can wrap it in R inline chunk like this `` `r knitr::inline_expr('chunk_reveal("walrus", title = "## Walrus operator")')` ``
Okay, there must be something different is our settings as I am not seeing the "". I am not sure that what I am getting is what you wast but it is different from your results.