This has come up many times before. A lot of people say its unnecessary. Personally I like it, and it could add to the performances. Best Cast Recording is a Grammy category, but I think it would be nice to honor songwriters with a good song in a overall undeserving score.
Problems that arise:
Do some shows get 2 performances (1 for best musical 1 for best song?)
If only 1 performance it could cost a best leading actor/actress nominee the chance to perform.
If a song is good enough for a Tony, shouldn’t the score be nominated? Which results in double awards for more or less the same category.
You would need producers to petition for 1 or 2 songs from their show to be nominated. You can’t expect the nominating committee to rate every single song, from every show.
If they did it, it would have to be named something like Best New Song Written for the Stage. To disqualify songs from Jukebox musicals and movie musicals etc.
"Have they come yet?"