I'm not sure I understand your use case entirely, but have you considered writing these blocks of text into a .txt, and then adding a navi snippet such as cat iostat_commands.txt?

support for multiline code-blocks would be great. I find it hard to maintain them after squashing them all in one line

@kqvanity Multiline code-block is already supported. See multiline-snippets.
You can also write cheats in Markdown with the extension .cheat.md, although this is not mentioned in the documentation.
In .cheat.md files, you can use three backtick code-blocks.

# multiline sample
```
echo hello \
    world
```

The multiline snippets doesn't show as multiple lines in the fuzzy search table, it's Also, it doesn't seem possible to have the comment span multiple lines, is it ?
Thanks for the .md extension, I find it more intuitive to write multiple lines

The main suggestion therefore becomes 2 requests:

• can we have multiple lines of comments before a command or code-block ?
• can we have the multiple lines code blocks (and multiple lines comments) displayed as multiple lines in the fuzzy search table ?

can we have multiple lines of comments before a command or code-block ?

We can write multiple lines of comments using ;. But this is not displayed in the fuzzy search table.

# hello world
; This is a metacomment.
; Not displayed in the fuzzy search table.
echo hello world

can we have the multiple lines code blocks (and multiple lines comments) displayed as multiple lines in the fuzzy search table ?

Although I think we cannot have multiple lines code blocks in the fuzzy search table, it can be configured to display it in the preview.
Try the configuration in the comment.

Sorry, I should have made myself clearer: I believe it would be very useful to have multiple lines of description.

And I believe it is possible to show multiple lines in the finder, as fzf already allows it (for the commands history):