I have found the facility whereby the "Key Change" panel overlays the instrument keyboard and is live while playing to be excellent. Especially as it does not get in the way of using the x-axis for volume control when playing.
It would be useful to have a similar facility for the on/off control of loops while playing live. Functionally it would be the same as the Mixer but without the volume setting (which would be set as normal by the Mixer). This facility would provide normal access to the keyboard (including x-axis volume) and enable the quick turning on or off one or several loops while playing on the keyboard. Perhaps the first four letters of the name of each loop could be shown on tabs the same size as the Key Change note tabs.
I really like the ability to use the Session Record to merge loops. It is easy to produce a series of merged loops which can form the basis for a live performance.
I also really like the ability to export WAV mixes from other Iphone apps and import to Thumbjam as a new loop. Session record the live final mix and add as background to a video. Brilliant.