Yes, @teh_g is correct, global moderators are special in that they will always have moderate privilege outside of the privileges page. Unfortunately it doesn't look as though you will be able to restrict gmods from their moderation privileges for this forum -- it's quite an odd use case!
So, when purging a category with a few coughtwentythousandcough posts, everything crashes, including the VPS due to lack of resources. I'll be honest, didn't expect it to work, but you don't find out unless you try.
However even a category with 20-30 topics can take a while to actually purge. Might be worth adding a similar thing to Restarting NodeBB along the lines of "Purging".
EDIT: Don't know why I put this in bug reports, probably more a feature request.
Lack of resources :neckbeard: Didn't think that was possible... I imagine we're just running it all in parallel, and exhausting fileopen limits or something like that...
Will have to ping @baris to see how he's actually implementing it.
@julian It surprised me to be honest. The forum died, so I went to check the logs, computer said no. Couldn't even reboot the VPS from terminal, had to go into Digital Ocean and do it from there...
Made some changes here to speed up the category purge.
I'm not sure how much it will help though since src/posts/delete.js has still quite a bit of work to do to prune each post.
@baris Nicely done. No more lack of resource errors. Have some reputation. As it appears I've overtaken you.