For relays, there is an easy answer: compliance testing apps. Like the check your DNS, or website for SEO applications. I think nostr:nprofile1qqswuyd9ml6qcxd92h6pleptfrcqucvvjy39vg4wx7mv9wm8kakyujgpypmhxue69uhkx6r0wf6hxtndd94k2erfd3nk2u3wvdhk6w35xs6z7qgwwaehxw309ahx7uewd3hkctcpypmhxue69uhkummnw3ezuetfde6kuer6wasku7nfvuh8xurpvdjj7a0nq40 started one.  

 yeah, a test of client is not so easy to do... i have images of macro recorders and using key navigation and injecting it into the input stream via an extension for web clients at least