Thx Arlo... That's a good question. For me, I think it would be nice to have the ability to set a pause prior to an individual recording. Oh and to confirm, I am describing this for live playing in "perform" mode (haven't updated to 4.x yet). Between songs I may have different time needs so the ability to manually set each would give some versatility. I'm guessing it would be an easier add as a global setting for you, but as long as I know the time there would be no surprises as to when the actual recording begins. This is especially true on "home" recorded backtracks.
I also pondered maybe a click track or similar but I think that would get very redundant for an audience and be sort of cheesy sounding. My probable solution is to get more proficient with my recordings in garage band, but I think this option would be nice.
As always, thanks Arlo!