The first use case was a request from nostr:nprofile1qqs8y6s7ycwvv36xwn5zsh3e2xemkyumaxnh85dv7jwus6xmscdpcygprpmhxue69uhkv6tvw3jhytnwdaehgu3wwa5kuef0ekucf3 for a site he could use to have someone sign an event that he had constructed and send the signed event back to him for publishing. The second use case was a request from nostr:nprofile1qqsgdp0taan9xwxadyc79nxl8svanu895yr8eyv0ytnss8p9tru047qpz3mhxue69uhhyetvv9ujuerpd46hxtnfduqs6amnwvaz7tmwdaejumr0dsq3samnwvaz7tmwdaehgu3wwdc8ymmkdahhxapwdekqgd20r7 to be able to easily publish a signed event when his usual client wasn't publishing successfully.