I'm filing this task to ask for a performance review of the Blackout extension. The code to be reviewed is not master, but instead this patch. The main concern here should be using the MediaWikiPerformAction hook, although it shouldn't be a big deal.
I have added the Performance-Team tag to task T198890 because this extension requires a completely different architecture to be compliant with operational requirements for Wikipedia. See T198890#4550160 for more information.
Once this extension is built and ready for deployment review, I believe it will be simple enough and front-end performance will not be critical enough to require additional sign-off. The Security review will suffice. Instead, I recommend Performance and (if needed) TechCom involvement with the architecture of the extension before it is built.