Here are two features I'd really like to have in the Au3 metronome. One's small, one's big.
1 I'd like to be able to choose my own metronome sounds. Just lob a wav file I've got into the metronome and use that sound - that's what I'd like.
2 I'd like to be able to vary metronome tempo within a session. I use click tracks for most of my work because I work with collaborators online and they usually demand a click track. But click tracks don't work for things like ritardando. Other softwares do this, but I don't want to lay out hundreds of dollars plus the time spent on a new learning curve just so that I can enjoy a fully-functional metronome. I'm much rather lay out another hundred dollars on a new version of Audition.
This metronome issue's a biggie for me. I work with click tracks all the time.