More usability offline (keep saved songs in the database to add when needed)
Our church meeting place has no wi-fi (crazy, I know) and so we prepare everything before we get there. If we were to want to add a song last minute, though, we can't even add a song that was cached in "My Songs" without an internet connection.
I really hope in future versions, we'll be able to access songs that are saved locally to help with locations like ours or also times when you might go on a retreat to somewhere with spotty internet.
Reuben, One thing that might aid your issue is to export the whole service as a backup, and take it to church on a pendrive. Ideally things would sync without this, but if you're having specific issues then the ability to whip a pen drive out of your back pocket and recover it to the local computer in the absence of internet access could save the day. Of course this doesn't help if you need to add a song at the last minute as was asked in the opening post.
We are located in a rural area where the only available internet is through long-distance wireless signal, making for an unreliable internet connection. There have been numerous times where the internet wouldn't connect so the worship leader couldn't do anything with proclaim. If "my songs" were stored locally (and perhaps online), it would eliminate the totality of the predicament. PLEASE strongly consider this!
Charles Philip commented
I Agree that songs should be store in a local cache as well, and I have experienced a case where we typed out a new song that someone wrote, and a few months later when we wanted to sing it again, we couldn't find it. And we were in fact connected to the internet. So this may be a different issue, but it will be resolved if songs are stored locally.