I made some edits to this answer and since I was editing anyway, I changed some text from quote blocks to headings to make it clearer that they were not quoting from anywhere, but simply providing highlighting of the text.
In case anyone is unfamiliar, during writing or editing quote blocks are indicated in markdown like this:
> Quoted text
and they appear in the rendered post like this:
Quoted text
Headings are indicated in markdown like this:
# Heading 1
## Heading 2
### Heading 3
and they appear in the rendered post like this:
Heading 1
Heading 2
Heading 3
I guessed that Heading 3 would match the posters intention best.
I've used quote blocks to highlight sections of text in the past, and seen it cause confusion because people expect it to be a quote from somewhere. I therefore avoid this now, using quote blocks only for actual quotations. Even where it is clear from the context, the moment it takes to work out that this quote block should not be interpreted as a quote breaks the flow of reading a post, causing delay and discomfort.
On our site we will often have reason to quote a section of a paper, and since this is also common on other Stack Exchange sites, many of our readers will associate the particular style of Stack Exchange quote blocks with quotations.
To what extent should we edit other people's posts to replace quote blocks with headings/bold/italics?
Should we edit only when also editing for another reason or is this sufficient for an independent edit? Should we respect the right of a poster to rollback the edit and use quote blocks as they wish, or should we have a rule to avoid confusion?