My preferred invocation of codeblocks to avoid tabbing in is with three backticks:
```/
codeblock
```/
(omitting the /)
After struggling to get this highlighting to work in Drafts, I checked to see which flavor(s) of markdown support it, and it seems GitHub is the only flavor out of the three in Drafts (unless I’m misreading documentation) that supports this. Playing around with the Mac preview features, all three are exporting with three backticks as codeblocks, but none highlight the syntax (including GitHub Markdown). While the documentation page indicates that none of these will change the syntax highlighting, it’d be really valuable to me to have syntax highlighting add three backticks (in any flavors) for codeblocks, the same as an indent currently does.