Good idea! I always keep the TC and click channels visible on all my layers, so I can immediately see when the song starts and tap 1 or two bars before the song actually starts. It sacrifices two channels on a smaller S3000 surface, but it helps.
This would be cool. Click channel as automatic tap tempo if needed. Makes life easier in situations with limited prep when bpm for different songs is not available beforehand. I also think tempo tapping always eats focus a little.