I’ve been annoyed by the “copy !communityname@server.host to your instance’s search” aspect of joining new communities. To make this more streamlined I created this extension to add a “Search on [myhomeinstance]” button on community pages. It’s currently submitted for approval in the chrome web store, which could take a few days, but you should be able to install it as an unpacked extension in developer mode today. Please let me know what you think and if you have any suggestions.
The latest version on GitHub works in developer edition. I’ll look in to getting it approved tomorrow.