The [[ https://github.com/InternationalScratchWiki/ScratchBlocks | version ]] of the ScratchBlocks extensions Miraheze is currently using has not been updated in 5 years and is archived. The code for the new version has been modified a lot and is in a [[ https://github.com/InternationalScratchWiki/mw-ScratchBlocks4 | different codebase ]] so it needs a security review. Performance-wise, the new version may be problematic as it loads JS from a website instead of a submodule (the current way) so that may be something Sysadmins want to consider.
The new version, if installed, would be used by [[ https://meta.miraheze.org/wiki/Talk:Help_center#Outdated_extension | scratchfanideaswiki ]] and `snapwikiwiki`.