"html_fragment" and "envir" functionality from Rmd?

I often used two features of Rmarkdown that I can't find equivalents for:

• the ability to create html fragments (html documents without headers) (with https://rmarkdown.rstudio.com/html_fragment_format.html), and
• the ability to compile a document with rmarkdown::render in a specified environment (via the envir argument) so that I could pass data objects to the document.

I can't find equivalents to these in quarto. I thought standalone: false might do it, based on the description ("Produce output with an appropriate header and footer (e.g. a standalone HTML, LaTeX, TEI, or RTF file, not a fragment)", from https://quarto.org/docs/reference/formats/html.html) but as far as I can tell, that option does not change the compilation of my documents at all.

Are there equivalents to these? Thanks!

Start by inspecting the R interface to Quarto and comparing its document-rendering entry point with rmarkdown::render, especially the envir argument and standalone: false format option. Verify whether equivalent workflows already exist; if not, establish the expected behavior for HTML fragments and passed data objects and add coverage for both.