They could lower the amount of songs to 5 to prevent abuse, but a change like this would make people's lives easier, and there are situations where certain abilities extend past a party but include the party, whether it be the way Smn healing magic in WKR hits all PCs, or accessioned embrava hitting another party, they have the capability to make it to where there is an answer to such a request within their spaghetti code. And Healing waltz could easily hit people outside of party if they wanted it to, I believe you're completely remembering any dev explanation that may have happened.